int igraph_sample_dirichlet(igraph_integer_t n, const igraph_vector_t *alpha,
igraph_matrix_t *res) {
igraph_integer_t len=igraph_vector_size(alpha);
igraph_integer_t i;
igraph_vector_t vec;
if (n < 0) {
IGRAPH_ERROR("Number of samples should be non-negative",
IGRAPH_EINVAL);
}
if (len < 2) {
IGRAPH_ERROR("Dirichlet parameter vector too short, must "
"have at least two entries", IGRAPH_EINVAL);
}
if (igraph_vector_min(alpha) <= 0) {
IGRAPH_ERROR("Dirichlet concentration parameters must be positive",
IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_matrix_resize(res, len, n));
RNG_BEGIN();
for (i = 0; i < n; i++) {
igraph_vector_view(&vec, &MATRIX(*res, 0, i), len);
igraph_rng_get_dirichlet(igraph_rng_default(), alpha, &vec);
}
RNG_END();
return 0;
}
int igraph_random_walk(const igraph_t *graph, igraph_vector_t *walk,
igraph_integer_t start, igraph_neimode_t mode,
igraph_integer_t steps,
igraph_random_walk_stuck_t stuck) {
/* TODO:
- multiple walks potentially from multiple start vertices
- weights
*/
igraph_lazy_adjlist_t adj;
igraph_integer_t vc = igraph_vcount(graph);
igraph_integer_t i;
if (start < 0 || start >= vc) {
IGRAPH_ERROR("Invalid start vertex", IGRAPH_EINVAL);
}
if (steps < 0) {
IGRAPH_ERROR("Invalid number of steps", IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_lazy_adjlist_init(graph, &adj, mode,
IGRAPH_DONT_SIMPLIFY));
IGRAPH_FINALLY(igraph_lazy_adjlist_destroy, &adj);
IGRAPH_CHECK(igraph_vector_resize(walk, steps));
RNG_BEGIN();
VECTOR(*walk)[0] = start;
for (i = 1; i < steps; i++) {
igraph_vector_t *neis;
igraph_integer_t nn;
neis = igraph_lazy_adjlist_get(&adj, start);
nn = igraph_vector_size(neis);
if (IGRAPH_UNLIKELY(nn == 0)) {
igraph_vector_resize(walk, i);
if (stuck == IGRAPH_RANDOM_WALK_STUCK_RETURN) {
break;
} else {
IGRAPH_ERROR("Random walk got stuck", IGRAPH_ERWSTUCK);
}
}
start = VECTOR(*walk)[i] = VECTOR(*neis)[ RNG_INTEGER(0, nn - 1) ];
}
RNG_END();
igraph_lazy_adjlist_destroy(&adj);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_dot_product_game(igraph_t *graph, const igraph_matrix_t *vecs,
igraph_bool_t directed) {
igraph_integer_t nrow=igraph_matrix_nrow(vecs);
igraph_integer_t ncol=igraph_matrix_ncol(vecs);
int i, j;
igraph_vector_t edges;
igraph_bool_t warned_neg=0, warned_big=0;
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
RNG_BEGIN();
for (i = 0; i < ncol; i++) {
int from=directed ? 0 : i+1;
igraph_vector_t v1;
igraph_vector_view(&v1, &MATRIX(*vecs, 0, i), nrow);
for (j = from; j < ncol; j++) {
igraph_real_t prob;
igraph_vector_t v2;
if (i==j) { continue; }
igraph_vector_view(&v2, &MATRIX(*vecs, 0, j), nrow);
igraph_lapack_ddot(&v1, &v2, &prob);
if (prob < 0 && ! warned_neg) {
warned_neg=1;
IGRAPH_WARNING("Negative connection probability in "
"dot-product graph");
} else if (prob > 1 && ! warned_big) {
warned_big=1;
IGRAPH_WARNING("Greater than 1 connection probability in "
"dot-product graph");
IGRAPH_CHECK(igraph_vector_push_back(&edges, i));
IGRAPH_CHECK(igraph_vector_push_back(&edges, j));
} else if (RNG_UNIF01() < prob) {
IGRAPH_CHECK(igraph_vector_push_back(&edges, i));
IGRAPH_CHECK(igraph_vector_push_back(&edges, j));
}
}
}
RNG_END();
igraph_create(graph, &edges, ncol, directed);
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_sample_sphere_surface(igraph_integer_t dim, igraph_integer_t n,
igraph_real_t radius,
igraph_bool_t positive,
igraph_matrix_t *res) {
igraph_integer_t i, j;
if (dim < 2) {
IGRAPH_ERROR("Sphere must be at least two dimensional to sample from "
"surface", IGRAPH_EINVAL);
}
if (n < 0) {
IGRAPH_ERROR("Number of samples must be non-negative", IGRAPH_EINVAL);
}
if (radius <= 0) {
IGRAPH_ERROR("Sphere radius must be positive", IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_matrix_resize(res, dim, n));
RNG_BEGIN();
for (i = 0; i < n; i++) {
igraph_real_t *col=&MATRIX(*res, 0, i);
igraph_real_t sum=0.0;
for (j = 0; j < dim; j++) {
col[j] = RNG_NORMAL(0, 1);
sum += col[j] * col[j];
}
sum = sqrt(sum);
for (j = 0; j < dim; j++) {
col[j] = radius * col[j] / sum;
}
if (positive) {
for (j = 0; j < dim; j++) {
col[j] = fabs(col[j]);
}
}
}
RNG_END();
return 0;
}
int igraph_sample_sphere_volume(igraph_integer_t dim, igraph_integer_t n,
igraph_real_t radius,
igraph_bool_t positive,
igraph_matrix_t *res) {
igraph_integer_t i, j;
/* Arguments are checked by the following call */
IGRAPH_CHECK(igraph_sample_sphere_surface(dim, n, radius, positive, res));
RNG_BEGIN();
for (i = 0; i < n; i++) {
igraph_real_t *col=&MATRIX(*res, 0, i);
igraph_real_t U=pow(RNG_UNIF01(), 1.0/dim);
for (j = 0; j < dim; j++) { col[j] *= U; }
}
RNG_END();
return 0;
}
int igraph_community_spinglass_single(const igraph_t *graph,
const igraph_vector_t *weights,
igraph_integer_t vertex,
igraph_vector_t *community,
igraph_real_t *cohesion,
igraph_real_t *adhesion,
igraph_integer_t *inner_links,
igraph_integer_t *outer_links,
igraph_integer_t spins,
igraph_spincomm_update_t update_rule,
igraph_real_t gamma) {
igraph_bool_t use_weights=0;
double prob;
ClusterList<NNode*> *cl_cur;
network *net;
PottsModel *pm;
char startnode[255];
/* Check arguments */
if (spins < 2 || spins > 500) {
IGRAPH_ERROR("Invalid number of spins", IGRAPH_EINVAL);
}
if (update_rule != IGRAPH_SPINCOMM_UPDATE_SIMPLE &&
update_rule != IGRAPH_SPINCOMM_UPDATE_CONFIG) {
IGRAPH_ERROR("Invalid update rule", IGRAPH_EINVAL);
}
if (weights) {
if (igraph_vector_size(weights) != igraph_ecount(graph)) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
use_weights=1;
}
if (gamma < 0.0) {
IGRAPH_ERROR("Invalid gamme value", IGRAPH_EINVAL);
}
if (vertex < 0 || vertex > igraph_vcount(graph)) {
IGRAPH_ERROR("Invalid vertex id", IGRAPH_EINVAL);
}
/* Check whether we have a single component */
igraph_bool_t conn;
IGRAPH_CHECK(igraph_is_connected(graph, &conn, IGRAPH_WEAK));
if (!conn) {
IGRAPH_ERROR("Cannot work with unconnected graph", IGRAPH_EINVAL);
}
net = new network;
net->node_list =new DL_Indexed_List<NNode*>();
net->link_list =new DL_Indexed_List<NLink*>();
net->cluster_list=new DL_Indexed_List<ClusterList<NNode*>*>();
/* Transform the igraph_t */
IGRAPH_CHECK(igraph_i_read_network(graph, weights,
net, use_weights, 0));
prob=2.0*net->sum_weights/double(net->node_list->Size())
/double(net->node_list->Size()-1);
pm=new PottsModel(net,(unsigned int)spins,update_rule);
/* initialize the random number generator */
RNG_BEGIN();
/* to be exected, if we want to find the community around a particular node*/
/* the initial conf is needed, because otherwise,
the degree of the nodes is not in the weight property, stupid!!! */
pm->assign_initial_conf(-1);
snprintf(startnode, 255, "%li", (long int)vertex+1);
pm->FindCommunityFromStart(gamma, prob, startnode, community,
cohesion, adhesion, inner_links, outer_links);
while (net->link_list->Size()) delete net->link_list->Pop();
while (net->node_list->Size()) delete net->node_list->Pop();
while (net->cluster_list->Size())
{
cl_cur=net->cluster_list->Pop();
while (cl_cur->Size()) cl_cur->Pop();
delete cl_cur;
}
delete net->link_list;
delete net->node_list;
delete net->cluster_list;
RNG_END();
delete net;
delete pm;
return 0;
}
int igraph_i_community_spinglass_orig(const igraph_t *graph,
const igraph_vector_t *weights,
igraph_real_t *modularity,
igraph_real_t *temperature,
igraph_vector_t *membership,
igraph_vector_t *csize,
igraph_integer_t spins,
igraph_bool_t parupdate,
igraph_real_t starttemp,
igraph_real_t stoptemp,
igraph_real_t coolfact,
igraph_spincomm_update_t update_rule,
igraph_real_t gamma) {
unsigned long changes, runs;
igraph_bool_t use_weights=0;
bool zeroT;
double kT, acc, prob;
ClusterList<NNode*> *cl_cur;
network *net;
PottsModel *pm;
/* Check arguments */
if (spins < 2 || spins > 500) {
IGRAPH_ERROR("Invalid number of spins", IGRAPH_EINVAL);
}
if (update_rule != IGRAPH_SPINCOMM_UPDATE_SIMPLE &&
update_rule != IGRAPH_SPINCOMM_UPDATE_CONFIG) {
IGRAPH_ERROR("Invalid update rule", IGRAPH_EINVAL);
}
if (weights) {
if (igraph_vector_size(weights) != igraph_ecount(graph)) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
use_weights=1;
}
if (coolfact < 0 || coolfact>=1.0) {
IGRAPH_ERROR("Invalid cooling factor", IGRAPH_EINVAL);
}
if (gamma < 0.0) {
IGRAPH_ERROR("Invalid gamme value", IGRAPH_EINVAL);
}
if (starttemp/stoptemp<1.0) {
IGRAPH_ERROR("starttemp should be larger in absolute value than stoptemp",
IGRAPH_EINVAL);
}
/* Check whether we have a single component */
igraph_bool_t conn;
IGRAPH_CHECK(igraph_is_connected(graph, &conn, IGRAPH_WEAK));
if (!conn) {
IGRAPH_ERROR("Cannot work with unconnected graph", IGRAPH_EINVAL);
}
net = new network;
net->node_list =new DL_Indexed_List<NNode*>();
net->link_list =new DL_Indexed_List<NLink*>();
net->cluster_list=new DL_Indexed_List<ClusterList<NNode*>*>();
/* Transform the igraph_t */
IGRAPH_CHECK(igraph_i_read_network(graph, weights,
net, use_weights, 0));
prob=2.0*net->sum_weights/double(net->node_list->Size())
/double(net->node_list->Size()-1);
pm=new PottsModel(net,(unsigned int)spins,update_rule);
/* initialize the random number generator */
RNG_BEGIN();
if ((stoptemp==0.0) && (starttemp==0.0)) zeroT=true; else zeroT=false;
if (!zeroT) kT=pm->FindStartTemp(gamma, prob, starttemp); else kT=stoptemp;
/* assign random initial configuration */
pm->assign_initial_conf(-1);
runs=0;
changes=1;
while (changes>0 && (kT/stoptemp>1.0 || (zeroT && runs<150))) {
IGRAPH_ALLOW_INTERRUPTION(); /* This is not clean.... */
runs++;
if (!zeroT) {
kT*=coolfact;
if (parupdate) {
changes=pm->HeatBathParallelLookup(gamma, prob, kT, 50);
} else {
acc=pm->HeatBathLookup(gamma, prob, kT, 50);
if (acc<(1.0-1.0/double(spins))*0.01) {
changes=0;
} else {
changes=1;
}
}
} else {
if (parupdate) {
changes=pm->HeatBathParallelLookupZeroTemp(gamma, prob, 50);
} else {
acc=pm->HeatBathLookupZeroTemp(gamma, prob, 50);
/* less than 1 percent acceptance ratio */
if (acc<(1.0-1.0/double(spins))*0.01) {
changes=0;
} else {
changes=1;
}
}
}
} /* while loop */
pm->WriteClusters(modularity, temperature, csize, membership, kT, gamma);
while (net->link_list->Size()) delete net->link_list->Pop();
while (net->node_list->Size()) delete net->node_list->Pop();
while (net->cluster_list->Size())
{
cl_cur=net->cluster_list->Pop();
while (cl_cur->Size()) cl_cur->Pop();
delete cl_cur;
}
delete net->link_list;
delete net->node_list;
delete net->cluster_list;
RNG_END();
delete net;
delete pm;
return 0;
}
int igraph_layout_gem(const igraph_t *graph, igraph_matrix_t *res,
igraph_bool_t use_seed, igraph_integer_t maxiter,
igraph_real_t temp_max, igraph_real_t temp_min,
igraph_real_t temp_init) {
igraph_integer_t no_nodes = igraph_vcount(graph);
igraph_vector_int_t perm;
igraph_vector_float_t impulse_x, impulse_y, temp, skew_gauge;
igraph_integer_t i;
float temp_global;
igraph_integer_t perm_pointer = 0;
float barycenter_x = 0.0, barycenter_y = 0.0;
igraph_vector_t phi;
igraph_vector_t neis;
const float elen_des2 = 128 * 128;
const float gamma = 1/16.0;
const float alpha_o = M_PI;
const float alpha_r = M_PI / 3.0;
const float sigma_o = 1.0 / 3.0;
const float sigma_r = 1.0 / 2.0 / no_nodes;
if (maxiter < 0) {
IGRAPH_ERROR("Number of iterations must be non-negative in GEM layout",
IGRAPH_EINVAL);
}
if (use_seed && (igraph_matrix_nrow(res) != no_nodes ||
igraph_matrix_ncol(res) != 2)) {
IGRAPH_ERROR("Invalid start position matrix size in GEM layout",
IGRAPH_EINVAL);
}
if (temp_max <= 0) {
IGRAPH_ERROR("Maximum temperature should be positive in GEM layout",
IGRAPH_EINVAL);
}
if (temp_min <= 0) {
IGRAPH_ERROR("Minimum temperature should be positive in GEM layout",
IGRAPH_EINVAL);
}
if (temp_init <= 0) {
IGRAPH_ERROR("Initial temperature should be positive in GEM layout",
IGRAPH_EINVAL);
}
if (temp_max < temp_init || temp_init < temp_min) {
IGRAPH_ERROR("Minimum <= Initial <= Maximum temperature is required "
"in GEM layout", IGRAPH_EINVAL);
}
if (no_nodes == 0) { return 0; }
IGRAPH_CHECK(igraph_vector_float_init(&impulse_x, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &impulse_x);
IGRAPH_CHECK(igraph_vector_float_init(&impulse_y, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &impulse_y);
IGRAPH_CHECK(igraph_vector_float_init(&temp, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &temp);
IGRAPH_CHECK(igraph_vector_float_init(&skew_gauge, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &skew_gauge);
IGRAPH_CHECK(igraph_vector_int_init_seq(&perm, 0, no_nodes-1));
IGRAPH_FINALLY(igraph_vector_int_destroy, &perm);
IGRAPH_VECTOR_INIT_FINALLY(&phi, no_nodes);
IGRAPH_VECTOR_INIT_FINALLY(&neis, 10);
RNG_BEGIN();
/* Initialization */
igraph_degree(graph, &phi, igraph_vss_all(), IGRAPH_ALL, IGRAPH_LOOPS);
if (!use_seed) {
const igraph_real_t width_half=no_nodes*100, height_half=width_half;
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 2));
for (i=0; i<no_nodes; i++) {
MATRIX(*res, i, 0) = RNG_UNIF(-width_half, width_half);
MATRIX(*res, i, 1) = RNG_UNIF(-height_half, height_half);
barycenter_x += MATRIX(*res, i, 0);
barycenter_y += MATRIX(*res, i, 1);
VECTOR(phi)[i] *= (VECTOR(phi)[i] / 2.0 + 1.0);
}
} else {
for (i=0; i<no_nodes; i++) {
barycenter_x += MATRIX(*res, i, 0);
barycenter_y += MATRIX(*res, i, 1);
VECTOR(phi)[i] *= (VECTOR(phi)[i] / 2.0 + 1.0);
}
}
igraph_vector_float_fill(&temp, temp_init);
temp_global = temp_init * no_nodes;
while (temp_global > temp_min * no_nodes && maxiter > 0) {
/* choose a vertex v to update */
igraph_integer_t u, v, nlen, j;
float px, py, pvx, pvy;
if (!perm_pointer) {
igraph_vector_int_shuffle(&perm);
perm_pointer=no_nodes-1;
}
v=VECTOR(perm)[perm_pointer--];
/* compute v's impulse */
px = (barycenter_x/no_nodes - MATRIX(*res, v, 0)) * gamma * VECTOR(phi)[v];
py = (barycenter_y/no_nodes - MATRIX(*res, v, 1)) * gamma * VECTOR(phi)[v];
px += RNG_UNIF(-32.0, 32.0);
py += RNG_UNIF(-32.0, 32.0);
for (u = 0; u < no_nodes; u++) {
float dx, dy, dist2;
if (u == v) { continue; }
dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
dist2=dx * dx + dy * dy;
if (dist2 != 0) {
px += dx * elen_des2 / dist2;
py += dy * elen_des2 / dist2;
}
}
IGRAPH_CHECK(igraph_neighbors(graph, &neis, v, IGRAPH_ALL));
nlen=igraph_vector_size(&neis);
for (j = 0; j < nlen; j++) {
igraph_integer_t u=VECTOR(neis)[j];
float dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
float dist2= dx * dx + dy * dy;
px -= dx * dist2 / (elen_des2 * VECTOR(phi)[v]);
py -= dy * dist2 / (elen_des2 * VECTOR(phi)[v]);
}
/* update v's position and temperature */
if (px != 0 || py != 0) {
float plen = sqrtf(px * px + py * py);
px *= VECTOR(temp)[v] / plen;
py *= VECTOR(temp)[v] / plen;
MATRIX(*res, v, 0) += px;
MATRIX(*res, v, 1) += py;
barycenter_x += px;
barycenter_y += py;
}
pvx=VECTOR(impulse_x)[v]; pvy=VECTOR(impulse_y)[v];
if (pvx != 0 || pvy != 0) {
float beta = atan2f(pvy - py, pvx - px);
float sin_beta = sinf(beta);
float sign_sin_beta = (sin_beta > 0) ? 1 : ((sin_beta < 0) ? -1 : 0);
float cos_beta = cosf(beta);
float abs_cos_beta = fabsf(cos_beta);
float old_temp=VECTOR(temp)[v];
if (sin(beta) >= sin(M_PI_2 + alpha_r / 2.0)) {
VECTOR(skew_gauge)[v] += sigma_r * sign_sin_beta;
}
if (abs_cos_beta >= cosf(alpha_o / 2.0)) {
VECTOR(temp)[v] *= sigma_o * cos_beta;
}
VECTOR(temp)[v] *= (1 - fabsf(VECTOR(skew_gauge)[v]));
if (VECTOR(temp)[v] > temp_max) { VECTOR(temp)[v] = temp_max; }
VECTOR(impulse_x)[v] = px;
VECTOR(impulse_y)[v] = py;
temp_global += VECTOR(temp)[v] - old_temp;
}
maxiter--;
} /* while temp && iter */
RNG_END();
igraph_vector_destroy(&neis);
igraph_vector_destroy(&phi);
igraph_vector_int_destroy(&perm);
igraph_vector_float_destroy(&skew_gauge);
igraph_vector_float_destroy(&temp);
igraph_vector_float_destroy(&impulse_y);
igraph_vector_float_destroy(&impulse_x);
IGRAPH_FINALLY_CLEAN(7);
return 0;
}
int igraph_forest_fire_game(igraph_t *graph, igraph_integer_t nodes,
igraph_real_t fw_prob, igraph_real_t bw_factor,
igraph_integer_t pambs, igraph_bool_t directed) {
igraph_vector_long_t visited;
long int no_of_nodes=nodes, actnode, i;
igraph_vector_t edges;
igraph_vector_t *inneis, *outneis;
igraph_i_forest_fire_data_t data;
igraph_dqueue_t neiq;
long int ambs=pambs;
igraph_real_t param_geom_out=1-fw_prob;
igraph_real_t param_geom_in=1-fw_prob*bw_factor;
if (fw_prob < 0) {
IGRAPH_ERROR("Forest fire model: 'fw_prob' should be between non-negative",
IGRAPH_EINVAL);
}
if (bw_factor < 0) {
IGRAPH_ERROR("Forest fire model: 'bw_factor' should be non-negative",
IGRAPH_EINVAL);
}
if (ambs < 0) {
IGRAPH_ERROR("Number of ambassadors ('ambs') should be non-negative",
IGRAPH_EINVAL);
}
if (fw_prob == 0 || ambs == 0) {
IGRAPH_WARNING("'fw_prob or ambs is zero, creating empty graph");
IGRAPH_CHECK(igraph_empty(graph, nodes, directed));
return 0;
}
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
inneis=igraph_Calloc(no_of_nodes, igraph_vector_t);
if (!inneis) {
IGRAPH_ERROR("Cannot run forest fire model", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, inneis);
outneis=igraph_Calloc(no_of_nodes, igraph_vector_t);
if (!outneis) {
IGRAPH_ERROR("Cannot run forest fire model", IGRAPH_ENOMEM);
}
IGRAPH_FINALLY(igraph_free, outneis);
data.inneis=inneis;
data.outneis=outneis;
data.no_of_nodes=no_of_nodes;
IGRAPH_FINALLY(igraph_i_forest_fire_free, &data);
for (i=0; i<no_of_nodes; i++) {
IGRAPH_CHECK(igraph_vector_init(inneis+i, 0));
IGRAPH_CHECK(igraph_vector_init(outneis+i, 0));
}
IGRAPH_CHECK(igraph_vector_long_init(&visited, no_of_nodes));
IGRAPH_FINALLY(igraph_vector_long_destroy, &visited);
IGRAPH_DQUEUE_INIT_FINALLY(&neiq, 10);
RNG_BEGIN();
#define ADD_EDGE_TO(nei) \
if (VECTOR(visited)[(nei)] != actnode+1) { \
VECTOR(visited)[(nei)] = actnode+1; \
IGRAPH_CHECK(igraph_dqueue_push(&neiq, nei)); \
IGRAPH_CHECK(igraph_vector_push_back(&edges, actnode)); \
IGRAPH_CHECK(igraph_vector_push_back(&edges, nei)); \
IGRAPH_CHECK(igraph_vector_push_back(outneis+actnode, nei)); \
IGRAPH_CHECK(igraph_vector_push_back(inneis+nei, actnode)); \
}
IGRAPH_PROGRESS("Forest fire: ", 0.0, NULL);
for (actnode=1; actnode < no_of_nodes; actnode++) {
IGRAPH_PROGRESS("Forest fire: ", 100.0*actnode/no_of_nodes, NULL);
IGRAPH_ALLOW_INTERRUPTION();
/* We don't want to visit the current vertex */
VECTOR(visited)[actnode] = actnode+1;
/* Choose ambassador(s) */
for (i=0; i<ambs; i++) {
long int a=RNG_INTEGER(0, actnode-1);
ADD_EDGE_TO(a);
}
while (!igraph_dqueue_empty(&neiq)) {
long int actamb=(long int) igraph_dqueue_pop(&neiq);
igraph_vector_t *outv=outneis+actamb;
igraph_vector_t *inv=inneis+actamb;
long int no_in=igraph_vector_size(inv);
long int no_out=igraph_vector_size(outv);
long int neis_out=(long int) RNG_GEOM(param_geom_out);
long int neis_in=(long int) RNG_GEOM(param_geom_in);
/* outgoing neighbors */
if (neis_out >= no_out) {
for (i=0; i<no_out; i++) {
long int nei=(long int) VECTOR(*outv)[i];
ADD_EDGE_TO(nei);
}
} else {
long int oleft=no_out;
for (i=0; i<neis_out && oleft > 0; ) {
long int which=RNG_INTEGER(0, oleft-1);
long int nei=(long int) VECTOR(*outv)[which];
VECTOR(*outv)[which] = VECTOR(*outv)[oleft-1];
VECTOR(*outv)[oleft-1] = nei;
if (VECTOR(visited)[nei] != actnode+1) {
ADD_EDGE_TO(nei);
i++;
}
oleft--;
}
}
/* incoming neighbors */
if (neis_in >= no_in) {
for (i=0; i<no_in; i++) {
long int nei=(long int) VECTOR(*inv)[i];
ADD_EDGE_TO(nei);
}
} else {
long int ileft=no_in;
for (i=0; i<neis_in && ileft > 0; ) {
long int which=RNG_INTEGER(0, ileft-1);
long int nei=(long int) VECTOR(*inv)[which];
VECTOR(*inv)[which] = VECTOR(*inv)[ileft-1];
VECTOR(*inv)[ileft-1] = nei;
if (VECTOR(visited)[nei] != actnode+1) {
ADD_EDGE_TO(nei);
i++;
}
ileft--;
}
}
} /* while neiq not empty */
} /* actnode < no_of_nodes */
#undef ADD_EDGE_TO
RNG_END();
IGRAPH_PROGRESS("Forest fire: ", 100.0, NULL);
igraph_dqueue_destroy(&neiq);
igraph_vector_long_destroy(&visited);
igraph_i_forest_fire_free(&data);
igraph_free(outneis);
igraph_free(inneis);
IGRAPH_FINALLY_CLEAN(5);
IGRAPH_CHECK(igraph_create(graph, &edges, nodes, directed));
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_bipartite_game_gnp(igraph_t *graph, igraph_vector_bool_t *types,
igraph_integer_t n1, igraph_integer_t n2,
igraph_real_t p, igraph_bool_t directed,
igraph_neimode_t mode) {
int retval=0;
igraph_vector_t edges, s;
int i;
if (p < 0.0 || p > 1.0) {
IGRAPH_ERROR("Invalid connection probability", IGRAPH_EINVAL);
}
if (types) {
IGRAPH_CHECK(igraph_vector_bool_resize(types, n1 + n2));
igraph_vector_bool_null(types);
for (i=n1; i<n1+n2; i++) {
VECTOR(*types)[i] = 1;
}
}
if (p == 0 || n1 * n2 < 1) {
IGRAPH_CHECK(retval=igraph_empty(graph, n1 + n2, directed));
} else if (p == 1.0) {
IGRAPH_CHECK(retval=igraph_full_bipartite(graph, types, n1, n2, directed,
mode));
} else {
long int to, from, slen;
double maxedges, last;
if (!directed || mode != IGRAPH_ALL) {
maxedges = n1 * n2;
} else {
maxedges = 2 * n1 * n2;
}
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
IGRAPH_VECTOR_INIT_FINALLY(&s, 0);
IGRAPH_CHECK(igraph_vector_reserve(&s, (long) (maxedges*p*1.1)));
RNG_BEGIN();
last=RNG_GEOM(p);
while (last < maxedges) {
IGRAPH_CHECK(igraph_vector_push_back(&s, last));
last += RNG_GEOM(p);
last += 1;
}
RNG_END();
slen=igraph_vector_size(&s);
IGRAPH_CHECK(igraph_vector_reserve(&edges, slen * 2));
for (i=0; i<slen; i++) {
if (!directed || mode != IGRAPH_ALL) {
to=(long) floor(VECTOR(s)[i]/n1);
from=(long) (VECTOR(s)[i] - ((igraph_real_t) to) * n1);
to += n1;
} else {
long int n1n2 = n1 * n2;
if (VECTOR(s)[i] < n1n2) {
to=(long) floor(VECTOR(s)[i]/n1);
from=(long) (VECTOR(s)[i] - ((igraph_real_t) to) * n1);
to += n1;
} else {
to=(long) floor( (VECTOR(s)[i]-n1n2) /n2);
from=(long) (VECTOR(s)[i] - n1n2 - ((igraph_real_t) to) * n2);
from += n1;
}
}
if (mode != IGRAPH_IN) {
igraph_vector_push_back(&edges, from);
igraph_vector_push_back(&edges, to);
} else {
igraph_vector_push_back(&edges, to);
igraph_vector_push_back(&edges, from);
}
}
igraph_vector_destroy(&s);
IGRAPH_FINALLY_CLEAN(1);
IGRAPH_CHECK(retval=igraph_create(graph, &edges, n1+n2, directed));
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
}
return retval;
}
int igraph_layout_kamada_kawai_3d(const igraph_t *graph, igraph_matrix_t *res,
igraph_bool_t use_seed, igraph_integer_t maxiter,
igraph_real_t epsilon, igraph_real_t kkconst,
const igraph_vector_t *weights,
const igraph_vector_t *minx, const igraph_vector_t *maxx,
const igraph_vector_t *miny, const igraph_vector_t *maxy,
const igraph_vector_t *minz, const igraph_vector_t *maxz) {
igraph_integer_t no_nodes=igraph_vcount(graph);
igraph_integer_t no_edges=igraph_ecount(graph);
igraph_real_t L, L0=sqrt(no_nodes);
igraph_matrix_t dij, lij, kij;
igraph_real_t max_dij;
igraph_vector_t D1, D2, D3;
igraph_integer_t i, j, m;
if (maxiter < 0) {
IGRAPH_ERROR("Number of iterations must be non-negatice in "
"Kamada-Kawai layout", IGRAPH_EINVAL);
}
if (kkconst <= 0) {
IGRAPH_ERROR("`K' constant must be positive in Kamada-Kawai layout",
IGRAPH_EINVAL);
}
if (use_seed && (igraph_matrix_nrow(res) != no_nodes ||
igraph_matrix_ncol(res) != 3)) {
IGRAPH_ERROR("Invalid start position matrix size in "
"3d Kamada-Kawai layout", IGRAPH_EINVAL);
}
if (weights && igraph_vector_size(weights) != no_edges) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
if (minx && igraph_vector_size(minx) != no_nodes) {
IGRAPH_ERROR("Invalid minx vector length", IGRAPH_EINVAL);
}
if (maxx && igraph_vector_size(maxx) != no_nodes) {
IGRAPH_ERROR("Invalid maxx vector length", IGRAPH_EINVAL);
}
if (minx && maxx && !igraph_vector_all_le(minx, maxx)) {
IGRAPH_ERROR("minx must not be greater than maxx", IGRAPH_EINVAL);
}
if (miny && igraph_vector_size(miny) != no_nodes) {
IGRAPH_ERROR("Invalid miny vector length", IGRAPH_EINVAL);
}
if (maxy && igraph_vector_size(maxy) != no_nodes) {
IGRAPH_ERROR("Invalid maxy vector length", IGRAPH_EINVAL);
}
if (miny && maxy && !igraph_vector_all_le(miny, maxy)) {
IGRAPH_ERROR("miny must not be greater than maxy", IGRAPH_EINVAL);
}
if (minz && igraph_vector_size(minz) != no_nodes) {
IGRAPH_ERROR("Invalid minz vector length", IGRAPH_EINVAL);
}
if (maxz && igraph_vector_size(maxz) != no_nodes) {
IGRAPH_ERROR("Invalid maxz vector length", IGRAPH_EINVAL);
}
if (minz && maxz && !igraph_vector_all_le(minz, maxz)) {
IGRAPH_ERROR("minz must not be greater than maxz", IGRAPH_EINVAL);
}
if (!use_seed) {
if (minx || maxx || miny || maxy || minz || maxz) {
const igraph_real_t width=sqrt(no_nodes), height=width, depth=width;
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 3));
RNG_BEGIN();
for (i=0; i<no_nodes; i++) {
igraph_real_t x1=minx ? VECTOR(*minx)[i] : -width/2;
igraph_real_t x2=maxx ? VECTOR(*maxx)[i] : width/2;
igraph_real_t y1=miny ? VECTOR(*miny)[i] : -height/2;
igraph_real_t y2=maxy ? VECTOR(*maxy)[i] : height/2;
igraph_real_t z1=minz ? VECTOR(*minz)[i] : -depth/2;
igraph_real_t z2=maxz ? VECTOR(*maxz)[i] : depth/2;
if (!igraph_finite(x1)) { x1 = -width/2; }
if (!igraph_finite(x2)) { x2 = width/2; }
if (!igraph_finite(y1)) { y1 = -height/2; }
if (!igraph_finite(y2)) { y2 = height/2; }
if (!igraph_finite(z1)) { z1 = -depth/2; }
if (!igraph_finite(z2)) { z2 = depth/2; }
MATRIX(*res, i, 0) = RNG_UNIF(x1, x2);
MATRIX(*res, i, 1) = RNG_UNIF(y1, y2);
MATRIX(*res, i, 2) = RNG_UNIF(z1, z2);
}
RNG_END();
} else {
igraph_layout_sphere(graph, res);
}
}
if (no_nodes <= 1) { return 0; }
IGRAPH_MATRIX_INIT_FINALLY(&dij, no_nodes, no_nodes);
IGRAPH_MATRIX_INIT_FINALLY(&kij, no_nodes, no_nodes);
IGRAPH_MATRIX_INIT_FINALLY(&lij, no_nodes, no_nodes);
IGRAPH_CHECK(igraph_shortest_paths_dijkstra(graph, &dij, igraph_vss_all(),
igraph_vss_all(), weights,
IGRAPH_ALL));
max_dij = 0.0;
for (i=0; i<no_nodes; i++) {
for (j=i+1; j<no_nodes; j++) {
if (!igraph_finite(MATRIX(dij, i, j))) { continue; }
if (MATRIX(dij, i, j) > max_dij) { max_dij = MATRIX(dij, i, j); }
}
}
for (i=0; i<no_nodes; i++) {
for (j=0; j<no_nodes; j++) {
if (MATRIX(dij, i, j) > max_dij) { MATRIX(dij, i, j) = max_dij; }
}
}
L = L0 / max_dij;
for (i=0; i<no_nodes; i++) {
for (j=0; j<no_nodes; j++) {
igraph_real_t tmp=MATRIX(dij, i, j) * MATRIX(dij, i, j);
if (i==j) { continue; }
MATRIX(kij, i, j) = kkconst / tmp;
MATRIX(lij, i, j) = L * MATRIX(dij, i, j);
}
}
/* Initialize delta */
IGRAPH_VECTOR_INIT_FINALLY(&D1, no_nodes);
IGRAPH_VECTOR_INIT_FINALLY(&D2, no_nodes);
IGRAPH_VECTOR_INIT_FINALLY(&D3, no_nodes);
for (m=0; m<no_nodes; m++) {
igraph_real_t myD1=0.0, myD2=0.0, myD3=0.0;
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t dx=MATRIX(*res, m, 0) - MATRIX(*res, i, 0);
igraph_real_t dy=MATRIX(*res, m, 1) - MATRIX(*res, i, 1);
igraph_real_t dz=MATRIX(*res, m, 2) - MATRIX(*res, i, 2);
igraph_real_t mi_dist=sqrt(dx * dx + dy * dy + dz * dz);
myD1 += MATRIX(kij, m, i) * (dx - MATRIX(lij, m, i) * dx / mi_dist);
myD2 += MATRIX(kij, m, i) * (dy - MATRIX(lij, m, i) * dy / mi_dist);
myD3 += MATRIX(kij, m, i) * (dz - MATRIX(lij, m, i) * dz / mi_dist);
}
VECTOR(D1)[m] = myD1;
VECTOR(D2)[m] = myD2;
VECTOR(D3)[m] = myD3;
}
for (j=0; j<maxiter; j++) {
igraph_real_t Ax=0.0, Ay=0.0, Az=0.0;
igraph_real_t Axx=0.0, Axy=0.0, Axz=0.0, Ayy=0.0, Ayz=0.0, Azz=0.0;
igraph_real_t max_delta, delta_x, delta_y, delta_z;
igraph_real_t old_x, old_y, old_z, new_x, new_y, new_z;
igraph_real_t detnum;
/* Select maximal delta */
m=0; max_delta=-1;
for (i=0; i<no_nodes; i++) {
igraph_real_t delta=(VECTOR(D1)[i] * VECTOR(D1)[i] +
VECTOR(D2)[i] * VECTOR(D2)[i] +
VECTOR(D3)[i] * VECTOR(D3)[i]);
if (delta > max_delta) {
m=i; max_delta=delta;
}
}
if (max_delta < epsilon) { break; }
old_x=MATRIX(*res, m, 0);
old_y=MATRIX(*res, m, 1);
old_z=MATRIX(*res, m, 2);
/* Calculate D1, D2 and D3, and other coefficients */
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t dx=old_x - MATRIX(*res, i, 0);
igraph_real_t dy=old_y - MATRIX(*res, i, 1);
igraph_real_t dz=old_z - MATRIX(*res, i, 2);
igraph_real_t dist=sqrt(dx * dx + dy * dy + dz *dz);
igraph_real_t den=dist * (dx * dx + dy * dy + dz * dz);
igraph_real_t k_mi=MATRIX(kij, m, i);
igraph_real_t l_mi=MATRIX(lij, m, i);
Axx += k_mi * (1 - l_mi * (dy*dy + dz*dz) / den);
Ayy += k_mi * (1 - l_mi * (dx*dx + dz*dz) / den);
Azz += k_mi * (1 - l_mi * (dx*dx + dy*dy) / den);
Axy += k_mi * l_mi * dx * dy / den;
Axz += k_mi * l_mi * dx * dz / den;
Ayz += k_mi * l_mi * dy * dz / den;
}
Ax = -VECTOR(D1)[m];
Ay = -VECTOR(D2)[m];
Az = -VECTOR(D3)[m];
/* Need to solve some linear equations, we just use Cramer's rule */
#define DET(a,b,c,d,e,f,g,h,i) ((a*e*i+b*f*g+c*d*h)-(c*e*g+b*d*i+a*f*h))
detnum = DET(Axx,Axy,Axz, Axy,Ayy,Ayz, Axz,Ayz,Azz);
delta_x = DET(Ax ,Ay ,Az , Axy,Ayy,Ayz, Axz,Ayz,Azz) / detnum;
delta_y = DET(Axx,Axy,Axz, Ax ,Ay ,Az , Axz,Ayz,Azz) / detnum;
delta_z = DET(Axx,Axy,Axz, Axy,Ayy,Ayz, Ax ,Ay ,Az ) / detnum;
new_x = old_x + delta_x;
new_y = old_y + delta_y;
new_z = old_z + delta_z;
/* Limits, if given */
if (minx && new_x < VECTOR(*minx)[m]) { new_x = VECTOR(*minx)[m]; }
if (maxx && new_x > VECTOR(*maxx)[m]) { new_x = VECTOR(*maxx)[m]; }
if (miny && new_y < VECTOR(*miny)[m]) { new_y = VECTOR(*miny)[m]; }
if (maxy && new_y > VECTOR(*maxy)[m]) { new_y = VECTOR(*maxy)[m]; }
if (minz && new_z < VECTOR(*minz)[m]) { new_z = VECTOR(*minz)[m]; }
if (maxz && new_z > VECTOR(*maxz)[m]) { new_z = VECTOR(*maxz)[m]; }
/* Update delta, only with/for the affected node */
VECTOR(D1)[m] = VECTOR(D2)[m] = VECTOR(D3)[m] = 0.0;
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t old_dx=old_x - MATRIX(*res, i, 0);
igraph_real_t old_dy=old_y - MATRIX(*res, i, 1);
igraph_real_t old_dz=old_z - MATRIX(*res, i, 2);
igraph_real_t old_mi_dist=sqrt(old_dx * old_dx + old_dy * old_dy +
old_dz * old_dz);
igraph_real_t new_dx=new_x - MATRIX(*res, i, 0);
igraph_real_t new_dy=new_y - MATRIX(*res, i, 1);
igraph_real_t new_dz=new_z - MATRIX(*res, i, 2);
igraph_real_t new_mi_dist=sqrt(new_dx * new_dx + new_dy * new_dy +
new_dz * new_dz);
VECTOR(D1)[i] -= MATRIX(kij, m, i) *
(-old_dx + MATRIX(lij, m, i) * old_dx / old_mi_dist);
VECTOR(D2)[i] -= MATRIX(kij, m, i) *
(-old_dy + MATRIX(lij, m, i) * old_dy / old_mi_dist);
VECTOR(D3)[i] -= MATRIX(kij, m, i) *
(-old_dz + MATRIX(lij, m, i) * old_dz / old_mi_dist);
VECTOR(D1)[i] += MATRIX(kij, m, i) *
(-new_dx + MATRIX(lij, m, i) * new_dx / new_mi_dist);
VECTOR(D2)[i] += MATRIX(kij, m, i) *
(-new_dy + MATRIX(lij, m, i) * new_dy / new_mi_dist);
VECTOR(D3)[i] += MATRIX(kij, m, i) *
(-new_dz + MATRIX(lij, m, i) * new_dz / new_mi_dist);
VECTOR(D1)[m] += MATRIX(kij, m, i) *
(new_dx - MATRIX(lij, m, i) * new_dx / new_mi_dist);
VECTOR(D2)[m] += MATRIX(kij, m, i) *
(new_dy - MATRIX(lij, m, i) * new_dy / new_mi_dist);
VECTOR(D3)[m] += MATRIX(kij, m, i) *
(new_dz - MATRIX(lij, m, i) * new_dz / new_mi_dist);
}
/* Update coordinates*/
MATRIX(*res, m, 0) = new_x;
MATRIX(*res, m, 1) = new_y;
MATRIX(*res, m, 2) = new_z;
}
igraph_vector_destroy(&D3);
igraph_vector_destroy(&D2);
igraph_vector_destroy(&D1);
igraph_matrix_destroy(&lij);
igraph_matrix_destroy(&kij);
igraph_matrix_destroy(&dij);
IGRAPH_FINALLY_CLEAN(6);
return 0;
}
int igraph_layout_i_fr(const igraph_t *graph,
igraph_matrix_t *res,
igraph_bool_t use_seed,
igraph_integer_t niter,
igraph_real_t start_temp,
const igraph_vector_t *weight,
const igraph_vector_t *minx,
const igraph_vector_t *maxx,
const igraph_vector_t *miny,
const igraph_vector_t *maxy) {
igraph_integer_t no_nodes=igraph_vcount(graph);
igraph_integer_t no_edges=igraph_ecount(graph);
igraph_integer_t i;
igraph_vector_float_t dispx, dispy;
igraph_real_t temp=start_temp;
igraph_real_t difftemp=start_temp / niter;
float width=sqrtf(no_nodes), height=width;
igraph_bool_t conn=1;
float C;
igraph_is_connected(graph, &conn, IGRAPH_WEAK);
if (!conn) { C = no_nodes * sqrtf(no_nodes); }
RNG_BEGIN();
if (!use_seed) {
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 2));
for (i=0; i<no_nodes; i++) {
igraph_real_t x1=minx ? VECTOR(*minx)[i] : -width/2;
igraph_real_t x2=maxx ? VECTOR(*maxx)[i] : width/2;
igraph_real_t y1=miny ? VECTOR(*miny)[i] : -height/2;
igraph_real_t y2=maxy ? VECTOR(*maxy)[i] : height/2;
if (!igraph_finite(x1)) { x1 = -sqrt(no_nodes)/2; }
if (!igraph_finite(x2)) { x2 = sqrt(no_nodes)/2; }
if (!igraph_finite(y1)) { y1 = -sqrt(no_nodes)/2; }
if (!igraph_finite(y2)) { y2 = sqrt(no_nodes)/2; }
MATRIX(*res, i, 0) = RNG_UNIF(x1, x2);
MATRIX(*res, i, 1) = RNG_UNIF(y1, y2);
}
}
IGRAPH_CHECK(igraph_vector_float_init(&dispx, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispx);
IGRAPH_CHECK(igraph_vector_float_init(&dispy, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispy);
for (i=0; i<niter; i++) {
igraph_integer_t v, u, e;
/* calculate repulsive forces, we have a special version
for unconnected graphs */
igraph_vector_float_null(&dispx);
igraph_vector_float_null(&dispy);
if (conn) {
for (v=0; v<no_nodes; v++) {
for (u=v+1; u<no_nodes; u++) {
float dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
float dlen=dx * dx + dy * dy;
if (dlen == 0) {
dx = RNG_UNIF01() * 1e-9;
dy = RNG_UNIF01() * 1e-9;
dlen = dx * dx + dy * dy;
}
VECTOR(dispx)[v] += dx/dlen;
VECTOR(dispy)[v] += dy/dlen;
VECTOR(dispx)[u] -= dx/dlen;
VECTOR(dispy)[u] -= dy/dlen;
}
}
} else {
for (v=0; v<no_nodes; v++) {
for (u=v+1; u<no_nodes; u++) {
float dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
float dlen, rdlen;
dlen=dx * dx + dy * dy;
if (dlen == 0) {
dx = RNG_UNIF(0, 1e-6);
dy = RNG_UNIF(0, 1e-6);
dlen = dx * dx + dy * dy;
}
rdlen=sqrt(dlen);
VECTOR(dispx)[v] += dx * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispy)[v] += dy * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispx)[u] -= dx * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispy)[u] -= dy * (C-dlen * rdlen) / (dlen*C);
}
}
}
/* calculate attractive forces */
for (e=0; e<no_edges; e++) {
/* each edges is an ordered pair of vertices v and u */
igraph_integer_t v=IGRAPH_FROM(graph, e);
igraph_integer_t u=IGRAPH_TO(graph, e);
igraph_real_t dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
igraph_real_t dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
igraph_real_t w=weight ? VECTOR(*weight)[e] : 1.0;
igraph_real_t dlen=sqrt(dx * dx + dy * dy) * w;
VECTOR(dispx)[v] -= (dx * dlen);
VECTOR(dispy)[v] -= (dy * dlen);
VECTOR(dispx)[u] += (dx * dlen);
VECTOR(dispy)[u] += (dy * dlen);
}
/* limit max displacement to temperature t and prevent from
displacement outside frame */
for (v=0; v<no_nodes; v++) {
igraph_real_t dx=VECTOR(dispx)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t dy=VECTOR(dispy)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t displen=sqrt(dx * dx + dy * dy);
igraph_real_t mx=fabs(dx) < temp ? dx : temp;
igraph_real_t my=fabs(dy) < temp ? dy : temp;
if (displen > 0) {
MATRIX(*res, v, 0) += (dx / displen) * mx;
MATRIX(*res, v, 1) += (dy / displen) * my;
}
if (minx && MATRIX(*res, v, 0) < VECTOR(*minx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*minx)[v];
}
if (maxx && MATRIX(*res, v, 0) > VECTOR(*maxx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*maxx)[v];
}
if (miny && MATRIX(*res, v, 1) < VECTOR(*miny)[v]) {
MATRIX(*res, v, 1) = VECTOR(*miny)[v];
}
if (maxy && MATRIX(*res, v, 1) > VECTOR(*maxy)[v]) {
MATRIX(*res, v, 1) = VECTOR(*maxy)[v];
}
}
temp -= difftemp;
}
RNG_END();
igraph_vector_float_destroy(&dispx);
igraph_vector_float_destroy(&dispy);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}
int igraph_layout_i_grid_fr(const igraph_t *graph,
igraph_matrix_t *res, igraph_bool_t use_seed,
igraph_integer_t niter, igraph_real_t start_temp,
const igraph_vector_t *weight, const igraph_vector_t *minx,
const igraph_vector_t *maxx, const igraph_vector_t *miny,
const igraph_vector_t *maxy) {
igraph_integer_t no_nodes=igraph_vcount(graph);
igraph_integer_t no_edges=igraph_ecount(graph);
float width=sqrtf(no_nodes), height=width;
igraph_2dgrid_t grid;
igraph_vector_float_t dispx, dispy;
igraph_real_t temp=start_temp;
igraph_real_t difftemp=start_temp / niter;
igraph_2dgrid_iterator_t vidit;
igraph_integer_t i;
const float cellsize=2.0;
RNG_BEGIN();
if (!use_seed) {
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 2));
for (i=0; i<no_nodes; i++) {
igraph_real_t x1=minx ? VECTOR(*minx)[i] : -width/2;
igraph_real_t x2=maxx ? VECTOR(*maxx)[i] : width/2;
igraph_real_t y1=miny ? VECTOR(*miny)[i] : -height/2;
igraph_real_t y2=maxy ? VECTOR(*maxy)[i] : height/2;
if (!igraph_finite(x1)) { x1 = -sqrt(no_nodes)/2; }
if (!igraph_finite(x2)) { x2 = sqrt(no_nodes)/2; }
if (!igraph_finite(y1)) { y1 = -sqrt(no_nodes)/2; }
if (!igraph_finite(y2)) { y2 = sqrt(no_nodes)/2; }
MATRIX(*res, i, 0) = RNG_UNIF(x1, x2);
MATRIX(*res, i, 1) = RNG_UNIF(y1, y2);
}
}
/* make grid */
IGRAPH_CHECK(igraph_2dgrid_init(&grid, res, -width/2, width/2, cellsize,
-height/2, height/2, cellsize));
IGRAPH_FINALLY(igraph_2dgrid_destroy, &grid);
/* place vertices on grid */
for (i=0; i<no_nodes; i++) {
igraph_2dgrid_add2(&grid, i);
}
IGRAPH_CHECK(igraph_vector_float_init(&dispx, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispx);
IGRAPH_CHECK(igraph_vector_float_init(&dispy, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispy);
for (i=0; i<niter; i++) {
igraph_integer_t v, u, e;
igraph_vector_float_null(&dispx);
igraph_vector_float_null(&dispy);
/* repulsion */
igraph_2dgrid_reset(&grid, &vidit);
while ( (v=igraph_2dgrid_next(&grid, &vidit)-1) != -1) {
while ( (u=igraph_2dgrid_next_nei(&grid, &vidit)-1) != -1) {
float dx=MATRIX(*res, v, 0)-MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1)-MATRIX(*res, u, 1);
float dlen=dx * dx + dy * dy;
if (dlen < cellsize * cellsize) {
VECTOR(dispx)[v] += dx/dlen;
VECTOR(dispy)[v] += dy/dlen;
VECTOR(dispx)[u] -= dx/dlen;
VECTOR(dispy)[u] -= dy/dlen;
}
}
}
/* attraction */
for (e=0; e<no_edges; e++) {
igraph_integer_t v=IGRAPH_FROM(graph, e);
igraph_integer_t u=IGRAPH_TO(graph, e);
igraph_real_t dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
igraph_real_t dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
igraph_real_t w=weight ? VECTOR(*weight)[e] : 1.0;
igraph_real_t dlen=sqrt(dx * dx + dy * dy) * w;
VECTOR(dispx)[v] -= (dx * dlen);
VECTOR(dispy)[v] -= (dy * dlen);
VECTOR(dispx)[u] += (dx * dlen);
VECTOR(dispy)[u] += (dy * dlen);
}
/* update */
for (v=0; v<no_nodes; v++) {
igraph_real_t dx=VECTOR(dispx)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t dy=VECTOR(dispy)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t displen=sqrt(dx * dx + dy * dy);
igraph_real_t mx=fabs(dx) < temp ? dx : temp;
igraph_real_t my=fabs(dy) < temp ? dy : temp;
if (displen > 0) {
MATRIX(*res, v, 0) += (dx / displen) * mx;
MATRIX(*res, v, 1) += (dy / displen) * my;
}
if (minx && MATRIX(*res, v, 0) < VECTOR(*minx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*minx)[v];
}
if (maxx && MATRIX(*res, v, 0) > VECTOR(*maxx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*maxx)[v];
}
if (miny && MATRIX(*res, v, 1) < VECTOR(*miny)[v]) {
MATRIX(*res, v, 1) = VECTOR(*miny)[v];
}
if (maxy && MATRIX(*res, v, 1) > VECTOR(*maxy)[v]) {
MATRIX(*res, v, 1) = VECTOR(*maxy)[v];
}
}
temp -= difftemp;
}
igraph_vector_float_destroy(&dispx);
igraph_vector_float_destroy(&dispy);
igraph_2dgrid_destroy(&grid);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int igraph_layout_kamada_kawai(const igraph_t *graph, igraph_matrix_t *res,
igraph_bool_t use_seed, igraph_integer_t maxiter,
igraph_real_t epsilon, igraph_real_t kkconst,
const igraph_vector_t *weights,
const igraph_vector_t *minx, const igraph_vector_t *maxx,
const igraph_vector_t *miny, const igraph_vector_t *maxy) {
igraph_integer_t no_nodes=igraph_vcount(graph);
igraph_integer_t no_edges=igraph_ecount(graph);
igraph_real_t L, L0=sqrt(no_nodes);
igraph_matrix_t dij, lij, kij;
igraph_real_t max_dij;
igraph_vector_t D1, D2;
igraph_integer_t i, j, m;
if (maxiter < 0) {
IGRAPH_ERROR("Number of iterations must be non-negatice in "
"Kamada-Kawai layout", IGRAPH_EINVAL);
}
if (kkconst <= 0) {
IGRAPH_ERROR("`K' constant must be positive in Kamada-Kawai layout",
IGRAPH_EINVAL);
}
if (use_seed && (igraph_matrix_nrow(res) != no_nodes ||
igraph_matrix_ncol(res) != 2)) {
IGRAPH_ERROR("Invalid start position matrix size in "
"Kamada-Kawai layout", IGRAPH_EINVAL);
}
if (weights && igraph_vector_size(weights) != no_edges) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
if (minx && igraph_vector_size(minx) != no_nodes) {
IGRAPH_ERROR("Invalid minx vector length", IGRAPH_EINVAL);
}
if (maxx && igraph_vector_size(maxx) != no_nodes) {
IGRAPH_ERROR("Invalid maxx vector length", IGRAPH_EINVAL);
}
if (minx && maxx && !igraph_vector_all_le(minx, maxx)) {
IGRAPH_ERROR("minx must not be greater than maxx", IGRAPH_EINVAL);
}
if (miny && igraph_vector_size(miny) != no_nodes) {
IGRAPH_ERROR("Invalid miny vector length", IGRAPH_EINVAL);
}
if (maxy && igraph_vector_size(maxy) != no_nodes) {
IGRAPH_ERROR("Invalid maxy vector length", IGRAPH_EINVAL);
}
if (miny && maxy && !igraph_vector_all_le(miny, maxy)) {
IGRAPH_ERROR("miny must not be greater than maxy", IGRAPH_EINVAL);
}
if (!use_seed) {
if (minx || maxx || miny || maxy) {
const igraph_real_t width=sqrt(no_nodes), height=width;
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 2));
RNG_BEGIN();
for (i=0; i<no_nodes; i++) {
igraph_real_t x1=minx ? VECTOR(*minx)[i] : -width/2;
igraph_real_t x2=maxx ? VECTOR(*maxx)[i] : width/2;
igraph_real_t y1=miny ? VECTOR(*miny)[i] : -height/2;
igraph_real_t y2=maxy ? VECTOR(*maxy)[i] : height/2;
if (!igraph_finite(x1)) { x1 = -width/2; }
if (!igraph_finite(x2)) { x2 = width/2; }
if (!igraph_finite(y1)) { y1 = -height/2; }
if (!igraph_finite(y2)) { y2 = height/2; }
MATRIX(*res, i, 0) = RNG_UNIF(x1, x2);
MATRIX(*res, i, 1) = RNG_UNIF(y1, y2);
}
RNG_END();
} else {
igraph_layout_circle(graph, res, /* order= */ igraph_vss_all());
}
}
if (no_nodes <= 1) { return 0; }
IGRAPH_MATRIX_INIT_FINALLY(&dij, no_nodes, no_nodes);
IGRAPH_MATRIX_INIT_FINALLY(&kij, no_nodes, no_nodes);
IGRAPH_MATRIX_INIT_FINALLY(&lij, no_nodes, no_nodes);
IGRAPH_CHECK(igraph_shortest_paths_dijkstra(graph, &dij, igraph_vss_all(),
igraph_vss_all(), weights,
IGRAPH_ALL));
max_dij = 0.0;
for (i=0; i<no_nodes; i++) {
for (j=i+1; j<no_nodes; j++) {
if (!igraph_finite(MATRIX(dij, i, j))) { continue; }
if (MATRIX(dij, i, j) > max_dij) { max_dij = MATRIX(dij, i, j); }
}
}
for (i=0; i<no_nodes; i++) {
for (j=0; j<no_nodes; j++) {
if (MATRIX(dij, i, j) > max_dij) { MATRIX(dij, i, j) = max_dij; }
}
}
L = L0 / max_dij;
for (i=0; i<no_nodes; i++) {
for (j=0; j<no_nodes; j++) {
igraph_real_t tmp=MATRIX(dij, i, j) * MATRIX(dij, i, j);
if (i==j) { continue; }
MATRIX(kij, i, j) = kkconst / tmp;
MATRIX(lij, i, j) = L * MATRIX(dij, i, j);
}
}
/* Initialize delta */
IGRAPH_VECTOR_INIT_FINALLY(&D1, no_nodes);
IGRAPH_VECTOR_INIT_FINALLY(&D2, no_nodes);
for (m=0; m<no_nodes; m++) {
igraph_real_t myD1=0.0, myD2=0.0;
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t dx=MATRIX(*res, m, 0) - MATRIX(*res, i, 0);
igraph_real_t dy=MATRIX(*res, m, 1) - MATRIX(*res, i, 1);
igraph_real_t mi_dist=sqrt(dx * dx + dy * dy);
myD1 += MATRIX(kij, m, i) * (dx - MATRIX(lij, m, i) * dx / mi_dist);
myD2 += MATRIX(kij, m, i) * (dy - MATRIX(lij, m, i) * dy / mi_dist);
}
VECTOR(D1)[m] = myD1;
VECTOR(D2)[m] = myD2;
}
for (j=0; j<maxiter; j++) {
igraph_real_t myD1=0.0, myD2=0.0, A=0.0, B=0.0, C=0.0;
igraph_real_t max_delta, delta_x, delta_y;
igraph_real_t old_x, old_y, new_x, new_y;
/* Select maximal delta */
m=0; max_delta=-1;
for (i=0; i<no_nodes; i++) {
igraph_real_t delta=(VECTOR(D1)[i] * VECTOR(D1)[i] +
VECTOR(D2)[i] * VECTOR(D2)[i]);
if (delta > max_delta) {
m=i; max_delta=delta;
}
}
if (max_delta < epsilon) { break; }
old_x=MATRIX(*res, m, 0);
old_y=MATRIX(*res, m, 1);
/* Calculate D1 and D2, A, B, C */
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t dx=old_x - MATRIX(*res, i, 0);
igraph_real_t dy=old_y - MATRIX(*res, i, 1);
igraph_real_t dist=sqrt(dx * dx + dy * dy);
igraph_real_t den=dist * (dx * dx + dy * dy);
A += MATRIX(kij, m, i) * (1 - MATRIX(lij, m, i) * dy * dy / den);
B += MATRIX(kij, m, i) * MATRIX(lij, m, i) * dx * dy / den;
C += MATRIX(kij, m, i) * (1 - MATRIX(lij, m, i) * dx * dx / den);
}
myD1 = VECTOR(D1)[m];
myD2 = VECTOR(D2)[m];
/* Need to solve some linear equations */
delta_y = (B * myD1 - myD2 * A) / (C * A - B * B);
delta_x = - (myD1 + B * delta_y) / A;
new_x = old_x + delta_x;
new_y = old_y + delta_y;
/* Limits, if given */
if (minx && new_x < VECTOR(*minx)[m]) { new_x = VECTOR(*minx)[m]; }
if (maxx && new_x > VECTOR(*maxx)[m]) { new_x = VECTOR(*maxx)[m]; }
if (miny && new_y < VECTOR(*miny)[m]) { new_y = VECTOR(*miny)[m]; }
if (maxy && new_y > VECTOR(*maxy)[m]) { new_y = VECTOR(*maxy)[m]; }
/* Update delta, only with/for the affected node */
VECTOR(D1)[m] = VECTOR(D2)[m] = 0.0;
for (i=0; i<no_nodes; i++) {
if (i==m) { continue; }
igraph_real_t old_dx=old_x - MATRIX(*res, i, 0);
igraph_real_t old_dy=old_y - MATRIX(*res, i, 1);
igraph_real_t old_mi_dist=sqrt(old_dx * old_dx + old_dy * old_dy);
igraph_real_t new_dx=new_x - MATRIX(*res, i, 0);
igraph_real_t new_dy=new_y - MATRIX(*res, i, 1);
igraph_real_t new_mi_dist=sqrt(new_dx * new_dx + new_dy * new_dy);
VECTOR(D1)[i] -= MATRIX(kij, m, i) *
(-old_dx + MATRIX(lij, m, i) * old_dx / old_mi_dist);
VECTOR(D2)[i] -= MATRIX(kij, m, i) *
(-old_dy + MATRIX(lij, m, i) * old_dy / old_mi_dist);
VECTOR(D1)[i] += MATRIX(kij, m, i) *
(-new_dx + MATRIX(lij, m, i) * new_dx / new_mi_dist);
VECTOR(D2)[i] += MATRIX(kij, m, i) *
(-new_dy + MATRIX(lij, m, i) * new_dy / new_mi_dist);
VECTOR(D1)[m] += MATRIX(kij, m, i) *
(new_dx - MATRIX(lij, m, i) * new_dx / new_mi_dist);
VECTOR(D2)[m] += MATRIX(kij, m, i) *
(new_dy - MATRIX(lij, m, i) * new_dy / new_mi_dist);
}
/* Update coordinates*/
MATRIX(*res, m, 0) = new_x;
MATRIX(*res, m, 1) = new_y;
}
igraph_vector_destroy(&D2);
igraph_vector_destroy(&D1);
igraph_matrix_destroy(&lij);
igraph_matrix_destroy(&kij);
igraph_matrix_destroy(&dij);
IGRAPH_FINALLY_CLEAN(5);
return 0;
}
int igraph_i_community_spinglass_negative(const igraph_t *graph,
const igraph_vector_t *weights,
igraph_real_t *modularity,
igraph_real_t *temperature,
igraph_vector_t *membership,
igraph_vector_t *csize,
igraph_integer_t spins,
igraph_bool_t parupdate,
igraph_real_t starttemp,
igraph_real_t stoptemp,
igraph_real_t coolfact,
igraph_spincomm_update_t update_rule,
igraph_real_t gamma,
/* igraph_matrix_t *adhesion, */
/* igraph_matrix_t *normalised_adhesion, */
/* igraph_real_t *polarization, */
igraph_real_t gamma_minus) {
unsigned long changes, runs;
igraph_bool_t use_weights=0;
bool zeroT;
double kT, acc;
ClusterList<NNode*> *cl_cur;
network *net;
PottsModelN *pm;
igraph_real_t d_n;
igraph_real_t d_p;
/* Check arguments */
if (parupdate) {
IGRAPH_ERROR("Parallel spin update not implemented with "
"negative gamma", IGRAPH_UNIMPLEMENTED);
}
if (spins < 2 || spins > 500) {
IGRAPH_ERROR("Invalid number of spins", IGRAPH_EINVAL);
}
if (update_rule != IGRAPH_SPINCOMM_UPDATE_SIMPLE &&
update_rule != IGRAPH_SPINCOMM_UPDATE_CONFIG) {
IGRAPH_ERROR("Invalid update rule", IGRAPH_EINVAL);
}
if (weights) {
if (igraph_vector_size(weights) != igraph_ecount(graph)) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
use_weights=1;
}
if (coolfact < 0 || coolfact>=1.0) {
IGRAPH_ERROR("Invalid cooling factor", IGRAPH_EINVAL);
}
if (gamma < 0.0) {
IGRAPH_ERROR("Invalid gamma value", IGRAPH_EINVAL);
}
if (starttemp/stoptemp<1.0) {
IGRAPH_ERROR("starttemp should be larger in absolute value than stoptemp",
IGRAPH_EINVAL);
}
/* Check whether we have a single component */
igraph_bool_t conn;
IGRAPH_CHECK(igraph_is_connected(graph, &conn, IGRAPH_WEAK));
if (!conn) {
IGRAPH_ERROR("Cannot work with unconnected graph", IGRAPH_EINVAL);
}
igraph_vector_minmax(weights, &d_n, &d_p);
if (d_n > 0) { d_n=0; }
if (d_p < 0) { d_p=0; }
d_n = -d_n;
net = new network;
net->node_list =new DL_Indexed_List<NNode*>();
net->link_list =new DL_Indexed_List<NLink*>();
net->cluster_list=new DL_Indexed_List<ClusterList<NNode*>*>();
/* Transform the igraph_t */
IGRAPH_CHECK(igraph_i_read_network(graph, weights,
net, use_weights, 0));
bool directed = igraph_is_directed(graph);
pm=new PottsModelN(net,(unsigned int)spins, directed);
/* initialize the random number generator */
RNG_BEGIN();
if ((stoptemp==0.0) && (starttemp==0.0)) zeroT=true; else zeroT=false;
//Begin at a high enough temperature
kT=pm->FindStartTemp(gamma, gamma_minus, starttemp);
/* assign random initial configuration */
pm->assign_initial_conf(true);
runs=0;
changes=1;
acc = 0;
while (changes>0 && (kT/stoptemp>1.0 || (zeroT && runs<150)))
{
IGRAPH_ALLOW_INTERRUPTION(); /* This is not clean.... */
runs++;
kT = kT*coolfact;
acc=pm->HeatBathLookup(gamma, gamma_minus, kT, 50);
if (acc<(1.0-1.0/double(spins))*0.001)
changes=0;
else
changes=1;
} /* while loop */
/* These are needed, otherwise 'modularity' is not calculated */
igraph_matrix_t adhesion, normalized_adhesion;
igraph_real_t polarization;
IGRAPH_MATRIX_INIT_FINALLY(&adhesion, 0, 0);
IGRAPH_MATRIX_INIT_FINALLY(&normalized_adhesion, 0, 0);
pm->WriteClusters(modularity, temperature, csize, membership,
&adhesion, &normalized_adhesion, &polarization,
kT, d_p, d_n, gamma, gamma_minus);
igraph_matrix_destroy(&normalized_adhesion);
igraph_matrix_destroy(&adhesion);
IGRAPH_FINALLY_CLEAN(2);
while (net->link_list->Size()) delete net->link_list->Pop();
while (net->node_list->Size()) delete net->node_list->Pop();
while (net->cluster_list->Size())
{
cl_cur=net->cluster_list->Pop();
while (cl_cur->Size()) cl_cur->Pop();
delete cl_cur;
}
RNG_END();
return 0;
}
int igraph_layout_fruchterman_reingold_3d(const igraph_t *graph,
igraph_matrix_t *res,
igraph_bool_t use_seed,
igraph_integer_t niter,
igraph_real_t start_temp,
const igraph_vector_t *weight,
const igraph_vector_t *minx,
const igraph_vector_t *maxx,
const igraph_vector_t *miny,
const igraph_vector_t *maxy,
const igraph_vector_t *minz,
const igraph_vector_t *maxz) {
igraph_integer_t no_nodes=igraph_vcount(graph);
igraph_integer_t no_edges=igraph_ecount(graph);
igraph_integer_t i;
igraph_vector_float_t dispx, dispy, dispz;
igraph_real_t temp=start_temp;
igraph_real_t difftemp=start_temp / niter;
float width=sqrtf(no_nodes), height=width, depth=width;
igraph_bool_t conn=1;
float C;
if (niter < 0) {
IGRAPH_ERROR("Number of iterations must be non-negative in "
"Fruchterman-Reingold layout", IGRAPH_EINVAL);
}
if (use_seed && (igraph_matrix_nrow(res) != no_nodes ||
igraph_matrix_ncol(res) != 3)) {
IGRAPH_ERROR("Invalid start position matrix size in "
"Fruchterman-Reingold layout", IGRAPH_EINVAL);
}
if (weight && igraph_vector_size(weight) != igraph_ecount(graph)) {
IGRAPH_ERROR("Invalid weight vector length", IGRAPH_EINVAL);
}
if (minx && igraph_vector_size(minx) != no_nodes) {
IGRAPH_ERROR("Invalid minx vector length", IGRAPH_EINVAL);
}
if (maxx && igraph_vector_size(maxx) != no_nodes) {
IGRAPH_ERROR("Invalid maxx vector length", IGRAPH_EINVAL);
}
if (minx && maxx && !igraph_vector_all_le(minx, maxx)) {
IGRAPH_ERROR("minx must not be greater than maxx", IGRAPH_EINVAL);
}
if (miny && igraph_vector_size(miny) != no_nodes) {
IGRAPH_ERROR("Invalid miny vector length", IGRAPH_EINVAL);
}
if (maxy && igraph_vector_size(maxy) != no_nodes) {
IGRAPH_ERROR("Invalid maxy vector length", IGRAPH_EINVAL);
}
if (miny && maxy && !igraph_vector_all_le(miny, maxy)) {
IGRAPH_ERROR("miny must not be greater than maxy", IGRAPH_EINVAL);
}
if (minz && igraph_vector_size(minz) != no_nodes) {
IGRAPH_ERROR("Invalid minz vector length", IGRAPH_EINVAL);
}
if (maxz && igraph_vector_size(maxz) != no_nodes) {
IGRAPH_ERROR("Invalid maxz vector length", IGRAPH_EINVAL);
}
if (minz && maxz && !igraph_vector_all_le(minz, maxz)) {
IGRAPH_ERROR("minz must not be greater than maxz", IGRAPH_EINVAL);
}
igraph_is_connected(graph, &conn, IGRAPH_WEAK);
if (!conn) { C = no_nodes * sqrtf(no_nodes); }
RNG_BEGIN();
if (!use_seed) {
IGRAPH_CHECK(igraph_matrix_resize(res, no_nodes, 3));
for (i=0; i<no_nodes; i++) {
igraph_real_t x1=minx ? VECTOR(*minx)[i] : -width/2;
igraph_real_t x2=maxx ? VECTOR(*maxx)[i] : width/2;
igraph_real_t y1=miny ? VECTOR(*miny)[i] : -height/2;
igraph_real_t y2=maxy ? VECTOR(*maxy)[i] : height/2;
igraph_real_t z1=minz ? VECTOR(*minz)[i] : -depth/2;
igraph_real_t z2=maxz ? VECTOR(*maxz)[i] : depth/2;
MATRIX(*res, i, 0) = RNG_UNIF(x1, x2);
MATRIX(*res, i, 1) = RNG_UNIF(y1, y2);
MATRIX(*res, i, 2) = RNG_UNIF(z1, z2);
}
}
IGRAPH_CHECK(igraph_vector_float_init(&dispx, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispx);
IGRAPH_CHECK(igraph_vector_float_init(&dispy, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispy);
IGRAPH_CHECK(igraph_vector_float_init(&dispz, no_nodes));
IGRAPH_FINALLY(igraph_vector_float_destroy, &dispz);
for (i=0; i<niter; i++) {
igraph_integer_t v, u, e;
/* calculate repulsive forces, we have a special version
for unconnected graphs */
igraph_vector_float_null(&dispx);
igraph_vector_float_null(&dispy);
igraph_vector_float_null(&dispz);
if (conn) {
for (v=0; v<no_nodes; v++) {
for (u=v+1; u<no_nodes; u++) {
float dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
float dz=MATRIX(*res, v, 2) - MATRIX(*res, u, 2);
float dlen=dx * dx + dy * dy + dz * dz;
if (dlen == 0) {
dx = RNG_UNIF01() * 1e-9;
dy = RNG_UNIF01() * 1e-9;
dz = RNG_UNIF01() * 1e-9;
dlen = dx * dx + dy * dy + dz * dz;
}
VECTOR(dispx)[v] += dx/dlen;
VECTOR(dispy)[v] += dy/dlen;
VECTOR(dispz)[v] += dz/dlen;
VECTOR(dispx)[u] -= dx/dlen;
VECTOR(dispy)[u] -= dy/dlen;
VECTOR(dispz)[u] -= dz/dlen;
}
}
} else {
for (v=0; v<no_nodes; v++) {
for (u=v+1; u<no_nodes; u++) {
float dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
float dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
float dz=MATRIX(*res, v, 2) - MATRIX(*res, u, 2);
float dlen, rdlen;
dlen=dx * dx + dy * dy + dz * dz;
if (dlen == 0) {
dx = RNG_UNIF01() * 1e-9;
dy = RNG_UNIF01() * 1e-9;
dz = RNG_UNIF01() * 1e-9;
dlen = dx * dx + dy * dy + dz * dz;
}
rdlen=sqrt(dlen);
VECTOR(dispx)[v] += dx * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispy)[v] += dy * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispy)[v] += dz * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispx)[u] -= dx * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispy)[u] -= dy * (C-dlen * rdlen) / (dlen*C);
VECTOR(dispz)[u] -= dz * (C-dlen * rdlen) / (dlen*C);
}
}
}
/* calculate attractive forces */
for (e=0; e<no_edges; e++) {
/* each edges is an ordered pair of vertices v and u */
igraph_integer_t v=IGRAPH_FROM(graph, e);
igraph_integer_t u=IGRAPH_TO(graph, e);
igraph_real_t dx=MATRIX(*res, v, 0) - MATRIX(*res, u, 0);
igraph_real_t dy=MATRIX(*res, v, 1) - MATRIX(*res, u, 1);
igraph_real_t dz=MATRIX(*res, v, 2) - MATRIX(*res, u, 2);
igraph_real_t w=weight ? VECTOR(*weight)[e] : 1.0;
igraph_real_t dlen=sqrt(dx * dx + dy * dy + dz * dz) * w;
VECTOR(dispx)[v] -= (dx * dlen);
VECTOR(dispy)[v] -= (dy * dlen);
VECTOR(dispz)[v] -= (dz * dlen);
VECTOR(dispx)[u] += (dx * dlen);
VECTOR(dispy)[u] += (dy * dlen);
VECTOR(dispz)[u] += (dz * dlen);
}
/* limit max displacement to temperature t and prevent from
displacement outside frame */
for (v=0; v<no_nodes; v++) {
igraph_real_t dx=VECTOR(dispx)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t dy=VECTOR(dispy)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t dz=VECTOR(dispz)[v] + RNG_UNIF01() * 1e-9;
igraph_real_t displen=sqrt(dx * dx + dy * dy + dz * dz);
igraph_real_t mx=fabs(dx) < temp ? dx : temp;
igraph_real_t my=fabs(dy) < temp ? dy : temp;
igraph_real_t mz=fabs(dz) < temp ? dz : temp;
if (displen > 0) {
MATRIX(*res, v, 0) += (dx / displen) * mx;
MATRIX(*res, v, 1) += (dy / displen) * my;
MATRIX(*res, v, 2) += (dz / displen) * mz;
}
if (minx && MATRIX(*res, v, 0) < VECTOR(*minx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*minx)[v];
}
if (maxx && MATRIX(*res, v, 0) > VECTOR(*maxx)[v]) {
MATRIX(*res, v, 0) = VECTOR(*maxx)[v];
}
if (miny && MATRIX(*res, v, 1) < VECTOR(*miny)[v]) {
MATRIX(*res, v, 1) = VECTOR(*miny)[v];
}
if (maxy && MATRIX(*res, v, 1) > VECTOR(*maxy)[v]) {
MATRIX(*res, v, 1) = VECTOR(*maxy)[v];
}
if (minz && MATRIX(*res, v, 2) < VECTOR(*minz)[v]) {
MATRIX(*res, v, 2) = VECTOR(*minz)[v];
}
if (maxz && MATRIX(*res, v, 2) > VECTOR(*maxz)[v]) {
MATRIX(*res, v, 2) = VECTOR(*maxz)[v];
}
}
temp -= difftemp;
}
RNG_END();
igraph_vector_float_destroy(&dispx);
igraph_vector_float_destroy(&dispy);
igraph_vector_float_destroy(&dispz);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int igraph_random_sample(igraph_vector_t *res, igraph_integer_t l, igraph_integer_t h,
igraph_integer_t length) {
igraph_real_t N=h-l+1;
igraph_real_t n=length;
int retval;
igraph_real_t nreal=length;
igraph_real_t ninv=1.0/nreal;
igraph_real_t Nreal=N;
igraph_real_t Vprime;
igraph_real_t qu1=-n+1+N;
igraph_real_t qu1real=-nreal+1.0+Nreal;
igraph_real_t negalphainv=-13;
igraph_real_t threshold=-negalphainv*n;
igraph_real_t S;
igraph_vector_clear(res);
IGRAPH_CHECK(igraph_vector_reserve(res, length));
RNG_BEGIN();
Vprime=exp(log(RNG_UNIF01())*ninv);
while (n>1 && threshold < N) {
igraph_real_t X, U;
igraph_real_t limit, t;
igraph_real_t negSreal, y1, y2, top, bottom;
igraph_real_t nmin1inv=1.0/(-1.0+nreal);
while (1) {
while(1) {
X=Nreal*(-Vprime+1.0);
S=floor(X);
if (S==0) { S=1; }
if (S <qu1) { break; }
Vprime = exp(log(RNG_UNIF01())*ninv);
}
U=RNG_UNIF01();
negSreal=-S;
y1=exp(log(U*Nreal/qu1real)*nmin1inv);
Vprime=y1*(-X/Nreal+1.0)*(qu1real/(negSreal+qu1real));
if (Vprime <= 1.0) { break; }
y2=1.0;
top=-1.0+Nreal;
if (-1+n > S) {
bottom=-nreal+Nreal;
limit=-S+N;
} else {
bottom=-1.0+negSreal+Nreal;
limit=qu1;
}
for (t=-1+N; t>=limit; t--) {
y2=(y2*top)/bottom;
top=-1.0+top;
bottom=-1.0+bottom;
}
if (Nreal/(-X+Nreal) >= y1*exp(log(y2)*nmin1inv)) {
Vprime=exp(log(RNG_UNIF01())*nmin1inv);
break;
}
Vprime=exp(log(RNG_UNIF01())*ninv);
}
l+=S;
igraph_vector_push_back(res, l); /* allocated */
N=-S+(-1+N); Nreal=negSreal+(-1.0+Nreal);
n=-1+n; nreal=-1.0+nreal; ninv=nmin1inv;
qu1=-S+qu1; qu1real=negSreal+qu1real;
threshold=threshold+negalphainv;
}
if (n>1) {
retval=igraph_random_sample_alga(res, l, h, n);
} else {
retval=0;
S=floor(N*Vprime);
l+=S;
igraph_vector_push_back(res, l); /* allocated */
}
RNG_END();
return retval;
}
int igraph_pagerank(const igraph_t *graph, igraph_vector_t *vector,
igraph_real_t *value, const igraph_vs_t vids,
igraph_bool_t directed, igraph_real_t damping,
const igraph_vector_t *weights,
igraph_arpack_options_t *options) {
igraph_matrix_t values;
igraph_matrix_t vectors;
igraph_integer_t dirmode;
igraph_vector_t outdegree;
igraph_vector_t tmp;
long int i;
long int no_of_nodes=igraph_vcount(graph);
long int no_of_edges=igraph_ecount(graph);
options->n = igraph_vcount(graph);
options->nev = 1;
options->ncv = 3;
options->which[0]='L'; options->which[1]='M';
options->start=1; /* no random start vector */
directed = directed && igraph_is_directed(graph);
if (weights && igraph_vector_size(weights) != igraph_ecount(graph))
{
IGRAPH_ERROR("Invalid length of weights vector when calculating "
"PageRank scores", IGRAPH_EINVAL);
}
IGRAPH_MATRIX_INIT_FINALLY(&values, 0, 0);
IGRAPH_MATRIX_INIT_FINALLY(&vectors, options->n, 1);
if (directed) { dirmode=IGRAPH_IN; } else { dirmode=IGRAPH_ALL; }
IGRAPH_VECTOR_INIT_FINALLY(&outdegree, options->n);
IGRAPH_VECTOR_INIT_FINALLY(&tmp, options->n);
RNG_BEGIN();
if (!weights) {
igraph_adjlist_t adjlist;
igraph_i_pagerank_data_t data = { graph, &adjlist, damping,
&outdegree, &tmp };
IGRAPH_CHECK(igraph_degree(graph, &outdegree, igraph_vss_all(),
directed ? IGRAPH_OUT : IGRAPH_ALL, /*loops=*/ 0));
/* Avoid division by zero */
for (i=0; i<options->n; i++) {
if (VECTOR(outdegree)[i]==0) {
VECTOR(outdegree)[i]=1;
}
MATRIX(vectors, i, 0) = VECTOR(outdegree)[i];
}
IGRAPH_CHECK(igraph_adjlist_init(graph, &adjlist, dirmode));
IGRAPH_FINALLY(igraph_adjlist_destroy, &adjlist);
IGRAPH_CHECK(igraph_arpack_rnsolve(igraph_i_pagerank,
&data, options, 0, &values, &vectors));
igraph_adjlist_destroy(&adjlist);
IGRAPH_FINALLY_CLEAN(1);
} else {
igraph_adjedgelist_t adjedgelist;
igraph_i_pagerank_data2_t data = { graph, &adjedgelist, weights,
damping, &outdegree, &tmp };
IGRAPH_CHECK(igraph_adjedgelist_init(graph, &adjedgelist, dirmode));
IGRAPH_FINALLY(igraph_adjedgelist_destroy, &adjedgelist);
/* Weighted degree */
for (i=0; i<no_of_edges; i++) {
long int from=IGRAPH_FROM(graph, i);
long int to=IGRAPH_TO(graph, i);
igraph_real_t weight=VECTOR(*weights)[i];
VECTOR(outdegree)[from] += weight;
if (!directed) {
VECTOR(outdegree)[to] += weight;
}
}
/* Avoid division by zero */
for (i=0; i<options->n; i++) {
if (VECTOR(outdegree)[i]==0) {
VECTOR(outdegree)[i]=1;
}
MATRIX(vectors, i, 0) = VECTOR(outdegree)[i];
}
IGRAPH_CHECK(igraph_arpack_rnsolve(igraph_i_pagerank2,
&data, options, 0, &values, &vectors));
igraph_adjedgelist_destroy(&adjedgelist);
IGRAPH_FINALLY_CLEAN(1);
}
RNG_END();
igraph_vector_destroy(&tmp);
igraph_vector_destroy(&outdegree);
IGRAPH_FINALLY_CLEAN(2);
if (value) {
*value=MATRIX(values, 0, 0);
}
if (vector) {
long int i;
igraph_vit_t vit;
long int nodes_to_calc;
igraph_real_t sum=0;
for (i=0; i<no_of_nodes; i++) {
sum += MATRIX(vectors, i, 0);
}
IGRAPH_CHECK(igraph_vit_create(graph, vids, &vit));
IGRAPH_FINALLY(igraph_vit_destroy, &vit);
nodes_to_calc=IGRAPH_VIT_SIZE(vit);
IGRAPH_CHECK(igraph_vector_resize(vector, nodes_to_calc));
for (IGRAPH_VIT_RESET(vit), i=0; !IGRAPH_VIT_END(vit);
IGRAPH_VIT_NEXT(vit), i++) {
VECTOR(*vector)[i] = MATRIX(vectors, (long int)IGRAPH_VIT_GET(vit), 0);
VECTOR(*vector)[i] /= sum;
}
igraph_vit_destroy(&vit);
IGRAPH_FINALLY_CLEAN(1);
}
if (options->info) {
IGRAPH_WARNING("Non-zero return code from ARPACK routine!");
}
igraph_matrix_destroy(&vectors);
igraph_matrix_destroy(&values);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}