igraph_bool_t check_ev(const igraph_matrix_t *A,
const igraph_vector_t *values_real,
const igraph_vector_t *values_imag,
const igraph_matrix_t *vectors_left,
const igraph_matrix_t *vectors_right,
igraph_real_t tol) {
int n=igraph_matrix_nrow(A);
igraph_vector_t v_real, v_imag;
igraph_vector_t AV_real, AV_imag, lv_real, lv_imag;
igraph_vector_t null;
int i;
if (igraph_matrix_ncol(A) != n) { return 1; }
if (igraph_vector_size(values_real) != n) { return 1; }
if (igraph_vector_size(values_imag) != n) { return 1; }
if (igraph_matrix_nrow(vectors_left) != n) { return 1; }
if (igraph_matrix_ncol(vectors_left) != n) { return 1; }
if (igraph_matrix_nrow(vectors_right) != n) { return 1; }
if (igraph_matrix_ncol(vectors_right) != n) { return 1; }
igraph_vector_init(&AV_real, n);
igraph_vector_init(&AV_imag, n);
igraph_vector_init(&lv_real, n);
igraph_vector_init(&lv_imag, n);
igraph_vector_init(&null, n);
igraph_vector_null(&null);
for (i=0; i<n; i++) {
if (VECTOR(*values_imag)[i]==0.0) {
igraph_vector_view(&v_real, &MATRIX(*vectors_right, 0, i), n);
igraph_vector_view(&v_imag, VECTOR(null), n);
} else if (VECTOR(*values_imag)[i] > 0.0) {
igraph_vector_view(&v_real, &MATRIX(*vectors_right, 0, i), n);
igraph_vector_view(&v_imag, &MATRIX(*vectors_right, 0, i+1), n);
} else if (VECTOR(*values_imag)[i] < 0.0) {
igraph_vector_view(&v_real, &MATRIX(*vectors_right, 0, i-1), n);
igraph_vector_view(&v_imag, &MATRIX(*vectors_right, 0, i), n);
igraph_vector_scale(&v_imag, -1.0);
}
real_cplx_mult(A, &v_real, &v_imag, &AV_real, &AV_imag);
sc_cplx_cplx_mult(VECTOR(*values_real)[i], VECTOR(*values_imag)[i],
&v_real, &v_imag, &lv_real, &lv_imag);
if (igraph_vector_maxdifference(&AV_real, &lv_real) > tol ||
igraph_vector_maxdifference(&AV_imag, &lv_imag) > tol) {
igraph_vector_print(&AV_real); igraph_vector_print(&AV_imag);
igraph_vector_print(&lv_real); igraph_vector_print(&lv_imag);
return 1;
}
}
igraph_vector_destroy(&null);
igraph_vector_destroy(&AV_imag);
igraph_vector_destroy(&AV_real);
igraph_vector_destroy(&lv_imag);
igraph_vector_destroy(&lv_real);
return 0;
}
int igraph_lapack_dgetrs(igraph_bool_t transpose, const igraph_matrix_t *a,
igraph_vector_int_t *ipiv, igraph_matrix_t *b) {
char trans = transpose ? 'T' : 'N';
int n=(int) igraph_matrix_nrow(a);
int nrhs=(int) igraph_matrix_ncol(b);
int lda= n > 0 ? n : 1;
int ldb= n > 0 ? n : 1;
int info;
if (n != igraph_matrix_ncol(a)) {
IGRAPH_ERROR("Cannot LU solve matrix", IGRAPH_NONSQUARE);
}
if (n != igraph_matrix_nrow(b)) {
IGRAPH_ERROR("Cannot LU solve matrix, RHS of wrong size", IGRAPH_EINVAL);
}
igraphdgetrs_(&trans, &n, &nrhs, VECTOR(a->data), &lda, VECTOR(*ipiv),
VECTOR(b->data), &ldb, &info);
if (info < 0) {
switch(info) {
case -1:
IGRAPH_ERROR("Invalid transpose argument", IGRAPH_ELAPACK);
break;
case -2:
IGRAPH_ERROR("Invalid number of rows/columns", IGRAPH_ELAPACK);
break;
case -3:
IGRAPH_ERROR("Invalid number of RHS vectors", IGRAPH_ELAPACK);
break;
case -4:
IGRAPH_ERROR("Invalid LU matrix", IGRAPH_ELAPACK);
break;
case -5:
IGRAPH_ERROR("Invalid LDA parameter", IGRAPH_ELAPACK);
break;
case -6:
IGRAPH_ERROR("Invalid pivot vector", IGRAPH_ELAPACK);
break;
case -7:
IGRAPH_ERROR("Invalid RHS matrix", IGRAPH_ELAPACK);
break;
case -8:
IGRAPH_ERROR("Invalid LDB parameter", IGRAPH_ELAPACK);
break;
case -9:
IGRAPH_ERROR("Invalid info argument", IGRAPH_ELAPACK);
break;
default:
IGRAPH_ERROR("Unknown LAPACK error", IGRAPH_ELAPACK);
break;
}
}
return 0;
}
/* call-seq:
* graph.get_adjacency(type) -> Array
*
* Returns the adjacency matrix of a graph
*
*/
VALUE cIGraph_get_adjacency(VALUE self, VALUE mode){
igraph_t *graph;
igraph_get_adjacency_t pmode = NUM2INT(mode);
igraph_matrix_t res;
int i;
int j;
VALUE row;
VALUE path_length;
VALUE matrix = rb_ary_new();
int n;
Data_Get_Struct(self, igraph_t, graph);
n = igraph_vcount(graph);
//matrix to hold the results of the calculations
igraph_matrix_init(&res,n,n);
igraph_get_adjacency(graph,&res,pmode);
for(i=0; i<igraph_matrix_nrow(&res); i++){
row = rb_ary_new();
rb_ary_push(matrix,row);
for(j=0; j<igraph_matrix_ncol(&res); j++){
path_length = INT2NUM(MATRIX(res,i,j));
rb_ary_push(row,path_length);
}
}
igraph_matrix_destroy(&res);
return matrix;
}
int check_ev(const igraph_matrix_t *A, const igraph_vector_t *values,
const igraph_matrix_t *vectors) {
int i, n=igraph_matrix_nrow(A);
int ne=igraph_matrix_ncol(vectors);
igraph_vector_t v, lhs, rhs;
if (ne != igraph_vector_size(values)) {
printf("'values' and 'vectors' sizes do not match\n");
exit(1);
}
igraph_vector_init(&lhs, n);
igraph_vector_init(&rhs, n);
for (i=0; i<ne; i++) {
igraph_vector_view(&v, &MATRIX(*vectors, 0, i), n);
igraph_blas_dgemv(/*transpose=*/ 0, /*alpha=*/ 1, A, &v,
/*beta=*/ 0, &lhs);
igraph_vector_update(&rhs, &v);
igraph_vector_scale(&rhs, VECTOR(*values)[i]);
if (igraph_vector_maxdifference(&lhs, &rhs) > 1e-10) {
printf("LHS: "); igraph_vector_print(&lhs);
printf("RHS: "); igraph_vector_print(&rhs);
exit(2);
}
}
igraph_vector_destroy(&rhs);
igraph_vector_destroy(&lhs);
return 0;
}
int real_cplx_mult(const igraph_matrix_t *A,
const igraph_vector_t *v_real,
const igraph_vector_t *v_imag,
igraph_vector_t *res_real,
igraph_vector_t *res_imag) {
int n=igraph_vector_size(v_real);
int r, c;
if (igraph_matrix_nrow(A) != n ||
igraph_matrix_ncol(A) != n ||
igraph_vector_size(v_imag) != n) {
printf("Wrong matrix or vector size");
return 1;
}
igraph_vector_resize(res_real, n);
igraph_vector_resize(res_imag, n);
for (r=0; r<n; r++) {
igraph_real_t s_real=0.0;
igraph_real_t s_imag=0.0;
for (c=0; c<n; c++) {
s_real += MATRIX(*A, r, c) * VECTOR(*v_real)[c];
s_imag += MATRIX(*A, r, c) * VECTOR(*v_imag)[c];
}
VECTOR(*res_real)[r]=s_real;
VECTOR(*res_imag)[r]=s_imag;
}
return 0;
}
/* call-seq:
* matrix.ncol -> Integer
*
* Returns the number of columns in the matrix.
*/
VALUE cIGraph_matrix_ncol(VALUE self){
igraph_matrix_t *m;
Data_Get_Struct(self, igraph_matrix_t, m);
return LONG2FIX(igraph_matrix_ncol(m));
}
void print_matrix(igraph_matrix_t *m, FILE *f) {
long int i, j;
for (i=0; i<igraph_matrix_nrow(m); i++) {
for (j=0; j<igraph_matrix_ncol(m); j++) {
fprintf(f, " %li", (long int) MATRIX(*m, i, j));
}
fprintf(f, "\n");
}
}
void byrow(igraph_matrix_t *m) {
long int r=igraph_matrix_nrow(m), c=igraph_matrix_ncol(m);
long int n=0, i, j;
for (i=0; i<r; i++) {
for (j=0; j<c; j++) {
MATRIX(*m, i, j) = n++;
}
}
}
void print_matrix(igraph_matrix_t *m) {
long int i, j;
for (i=0; i<igraph_matrix_nrow(m); i++) {
for (j=0; j<igraph_matrix_ncol(m); j++) {
printf(" %g", MATRIX(*m, i, j));
}
printf("\n");
}
}
/* call-seq:
* graph.dijkstra_shortest_paths(varray,weights,mode) -> Array
*
* Calculates the length of the shortest paths from each of the vertices in
* the varray Array to all of the other vertices in the graph given a set of
* edge weights given in the weights Array. The result
* is returned as an Array of Array. Each top-level Array contains the results
* for a vertex in the varray Array. Each entry in the Array is the path length
* to another vertex in the graph in vertex order (the order the vertices were
* added to the graph. (This should probalby be changed to give a Hash of Hash
* to allow easier look up.)
*/
VALUE cIGraph_dijkstra_shortest_paths(VALUE self, VALUE from, VALUE weights, VALUE mode){
igraph_t *graph;
igraph_vs_t vids;
igraph_vector_t vidv;
igraph_vector_t wghts;
igraph_neimode_t pmode = NUM2INT(mode);
igraph_matrix_t res;
int i;
int j;
VALUE row;
VALUE path_length;
VALUE matrix = rb_ary_new();
int n_row;
int n_col;
Data_Get_Struct(self, igraph_t, graph);
n_row = NUM2INT(rb_funcall(from,rb_intern("length"),0));
n_col = igraph_vcount(graph);
//matrix to hold the results of the calculations
igraph_matrix_init(&res,n_row,n_col);
igraph_vector_init(&wghts,RARRAY_LEN(weights));
for(i=0;i<RARRAY_LEN(weights);i++){
VECTOR(wghts)[i] = NUM2DBL(RARRAY_PTR(weights)[i]);
}
//Convert an array of vertices to a vector of vertex ids
igraph_vector_init_int(&vidv,0);
cIGraph_vertex_arr_to_id_vec(self,from,&vidv);
//create vertex selector from the vecotr of ids
igraph_vs_vector(&vids,&vidv);
igraph_dijkstra_shortest_paths(graph,&res,vids,&wghts,pmode);
for(i=0; i<igraph_matrix_nrow(&res); i++){
row = rb_ary_new();
rb_ary_push(matrix,row);
for(j=0; j<igraph_matrix_ncol(&res); j++){
path_length = MATRIX(res,i,j) == n_col ? Qnil : rb_float_new(MATRIX(res,i,j));
rb_ary_push(row,path_length);
}
}
igraph_vector_destroy(&vidv);
igraph_matrix_destroy(&res);
igraph_vs_destroy(&vids);
igraph_vector_destroy(&wghts);
return matrix;
}
int print_matrix(const igraph_matrix_t *m) {
long int i, j, nrow=igraph_matrix_nrow(m), ncol=igraph_matrix_ncol(m);
for (i=0; i<nrow; i++) {
for (j=0; j<ncol; j++) {
printf("%.2g", (double)MATRIX(*m, i, j));
if (j!=ncol-1) { printf(" "); }
}
printf("\n");
}
return 0;
}
void print_matrix(igraph_matrix_t* m) {
long int nr=igraph_matrix_nrow(m);
long int nc=igraph_matrix_ncol(m);
long int i, j;
for (i=0; i<nr; i++) {
for (j=0; j<nc; j++) {
if (j!=0) { putchar(' '); }
printf("%d", (int)MATRIX(*m, i, j));
}
printf("\n");
}
}
int print_matrix(const igraph_matrix_t *m) {
long int nrow=igraph_matrix_nrow(m);
long int ncol=igraph_matrix_ncol(m);
long int i, j;
for (i=0; i<nrow; i++) {
printf("%li:", i);
for (j=0; j<ncol; j++) {
printf(" %3.0F", MATRIX(*m, i, j));
}
printf("\n");
}
return 0;
}
int igraph_lapack_dgetrf(igraph_matrix_t *a, igraph_vector_int_t *ipiv,
int *info) {
int m=(int) igraph_matrix_nrow(a);
int n=(int) igraph_matrix_ncol(a);
int lda=m > 0 ? m : 1;
igraph_vector_int_t *myipiv=ipiv, vipiv;
if (!ipiv) {
IGRAPH_CHECK(igraph_vector_int_init(&vipiv, m<n ? m : n));
IGRAPH_FINALLY(igraph_vector_int_destroy, &vipiv);
myipiv=&vipiv;
}
igraphdgetrf_(&m, &n, VECTOR(a->data), &lda, VECTOR(*myipiv), info);
if (*info > 0) {
IGRAPH_WARNING("LU: factor is exactly singular");
} else if (*info < 0) {
switch(*info) {
case -1:
IGRAPH_ERROR("Invalid number of rows", IGRAPH_ELAPACK);
break;
case -2:
IGRAPH_ERROR("Invalid number of columns", IGRAPH_ELAPACK);
break;
case -3:
IGRAPH_ERROR("Invalid input matrix", IGRAPH_ELAPACK);
break;
case -4:
IGRAPH_ERROR("Invalid LDA parameter", IGRAPH_ELAPACK);
break;
case -5:
IGRAPH_ERROR("Invalid pivot vector", IGRAPH_ELAPACK);
break;
case -6:
IGRAPH_ERROR("Invalid info argument", IGRAPH_ELAPACK);
break;
default:
IGRAPH_ERROR("Unknown LAPACK error", IGRAPH_ELAPACK);
break;
}
}
if (!ipiv) {
igraph_vector_int_destroy(&vipiv);
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;
}
/**
* \ingroup structural
* \function igraph_similarity_dice
* \brief Dice similarity coefficient.
*
* </para><para>
* The Dice similarity coefficient of two vertices is twice the number of common
* neighbors divided by the sum of the degrees of the vertices. This function
* calculates the pairwise Dice similarities for some (or all) of the vertices.
*
* \param graph The graph object to analyze
* \param res Pointer to a matrix, the result of the calculation will
* be stored here. The number of its rows and columns is the same
* as the number of vertex ids in \p vids.
* \param vids The vertex ids of the vertices for which the
* calculation will be done.
* \param mode The type of neighbors to be used for the calculation in
* directed graphs. Possible values:
* \clist
* \cli IGRAPH_OUT
* the outgoing edges will be considered for each node.
* \cli IGRAPH_IN
* the incoming edges will be considered for each node.
* \cli IGRAPH_ALL
* the directed graph is considered as an undirected one for the
* computation.
* \endclist
* \param loops Whether to include the vertices themselves as their own
* neighbors.
* \return Error code:
* \clist
* \cli IGRAPH_ENOMEM
* not enough memory for temporary data.
* \cli IGRAPH_EINVVID
* invalid vertex id passed.
* \cli IGRAPH_EINVMODE
* invalid mode argument.
* \endclist
*
* Time complexity: O(|V|^2 d),
* |V| is the number of vertices in the vertex iterator given, d is the
* (maximum) degree of the vertices in the graph.
*
* \sa \ref igraph_similarity_jaccard(), a measure very similar to the Dice
* coefficient
*
* \example examples/simple/igraph_similarity.c
*/
int igraph_similarity_dice(const igraph_t *graph, igraph_matrix_t *res,
const igraph_vs_t vids, igraph_neimode_t mode, igraph_bool_t loops) {
long int i, j, nr, nc;
IGRAPH_CHECK(igraph_similarity_jaccard(graph, res, vids, mode, loops));
nr = igraph_matrix_nrow(res);
nc = igraph_matrix_ncol(res);
for (i = 0; i < nr; i++) {
for (j = 0; j < nc; j++) {
igraph_real_t x = MATRIX(*res, i, j);
MATRIX(*res, i, j) = 2*x / (1+x);
}
}
return IGRAPH_SUCCESS;
}
/* call-seq:
* graph.cocitation(varray) -> Array
*
* Cocitation coupling.
*
* Two vertices are cocited if there is another vertex citing both of them.
* igraph_cocitation() simply counts how many types two vertices are cocited.
* The cocitation score for each given vertex and all other vertices in the
* graph will be calculated.
*
*/
VALUE cIGraph_cocitation(VALUE self, VALUE vs){
igraph_t *graph;
igraph_vs_t vids;
igraph_vector_t vidv;
igraph_matrix_t res;
int i;
int j;
VALUE row;
VALUE path_length;
VALUE matrix = rb_ary_new();
int n_row;
int n_col;
Data_Get_Struct(self, igraph_t, graph);
n_row = NUM2INT(rb_funcall(vs,rb_intern("length"),0));
n_col = igraph_vcount(graph);
//matrix to hold the results of the calculations
igraph_matrix_init(&res,n_row,n_col);
//Convert an array of vertices to a vector of vertex ids
igraph_vector_init_int(&vidv,0);
cIGraph_vertex_arr_to_id_vec(self,vs,&vidv);
//create vertex selector from the vecotr of ids
igraph_vs_vector(&vids,&vidv);
igraph_cocitation(graph,&res,vids);
for(i=0; i<igraph_matrix_nrow(&res); i++){
row = rb_ary_new();
rb_ary_push(matrix,row);
for(j=0; j<igraph_matrix_ncol(&res); j++){
path_length = INT2NUM(MATRIX(res,i,j));
rb_ary_push(row,path_length);
}
}
igraph_vector_destroy(&vidv);
igraph_matrix_destroy(&res);
igraph_vs_destroy(&vids);
return matrix;
}
int igraph_i_eigen_checks(const igraph_matrix_t *A,
const igraph_sparsemat_t *sA,
igraph_arpack_function_t *fun, int n) {
if ( (A?1:0)+(sA?1:0)+(fun?1:0) != 1) {
IGRAPH_ERROR("Exactly one of 'A', 'sA' and 'fun' must be given",
IGRAPH_EINVAL);
}
if (A) {
if (n != igraph_matrix_ncol(A) || n != igraph_matrix_nrow(A)) {
IGRAPH_ERROR("Invalid matrix", IGRAPH_NONSQUARE);
}
} else if (sA) {
if (n != igraph_sparsemat_ncol(sA) || n != igraph_sparsemat_nrow(sA)) {
IGRAPH_ERROR("Invalid matrix", IGRAPH_NONSQUARE);
}
}
return 0;
}
int igraph_lapack_dgeevx(igraph_lapack_dgeevx_balance_t balance,
const igraph_matrix_t *A,
igraph_vector_t *valuesreal,
igraph_vector_t *valuesimag,
igraph_matrix_t *vectorsleft,
igraph_matrix_t *vectorsright,
int *ilo, int *ihi, igraph_vector_t *scale,
igraph_real_t *abnrm,
igraph_vector_t *rconde,
igraph_vector_t *rcondv,
int *info) {
char balanc;
char jobvl= vectorsleft ? 'V' : 'N';
char jobvr= vectorsright ? 'V' : 'N';
char sense;
int n=(int) igraph_matrix_nrow(A);
int lda=n, ldvl=n, ldvr=n, lwork=-1;
igraph_vector_t work;
igraph_vector_int_t iwork;
igraph_matrix_t Acopy;
int error=*info;
igraph_vector_t *myreal=valuesreal, *myimag=valuesimag, vreal, vimag;
igraph_vector_t *myscale=scale, vscale;
if (igraph_matrix_ncol(A) != n) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeevx)", IGRAPH_NONSQUARE);
}
switch (balance) {
case IGRAPH_LAPACK_DGEEVX_BALANCE_NONE:
balanc='N';
break;
case IGRAPH_LAPACK_DGEEVX_BALANCE_PERM:
balanc='P';
break;
case IGRAPH_LAPACK_DGEEVX_BALANCE_SCALE:
balanc='S';
break;
case IGRAPH_LAPACK_DGEEVX_BALANCE_BOTH:
balanc='B';
break;
default:
IGRAPH_ERROR("Invalid 'balance' argument", IGRAPH_EINVAL);
break;
}
if (!rconde && !rcondv) {
sense='N';
} else if (rconde && !rcondv) {
sense='E';
} else if (!rconde && rcondv) {
sense='V';
} else {
sense='B';
}
IGRAPH_CHECK(igraph_matrix_copy(&Acopy, A));
IGRAPH_FINALLY(igraph_matrix_destroy, &Acopy);
IGRAPH_VECTOR_INIT_FINALLY(&work, 1);
IGRAPH_CHECK(igraph_vector_int_init(&iwork, n));
IGRAPH_FINALLY(igraph_vector_int_destroy, &iwork);
if (!valuesreal) {
IGRAPH_VECTOR_INIT_FINALLY(&vreal, n);
myreal=&vreal;
} else {
IGRAPH_CHECK(igraph_vector_resize(myreal, n));
}
if (!valuesimag) {
IGRAPH_VECTOR_INIT_FINALLY(&vimag, n);
myimag=&vimag;
} else {
IGRAPH_CHECK(igraph_vector_resize(myimag, n));
}
if (!scale) {
IGRAPH_VECTOR_INIT_FINALLY(&vscale, n);
myscale=&vscale;
} else {
IGRAPH_CHECK(igraph_vector_resize(scale, n));
}
if (vectorsleft) {
IGRAPH_CHECK(igraph_matrix_resize(vectorsleft, n, n));
}
if (vectorsright) {
IGRAPH_CHECK(igraph_matrix_resize(vectorsright, n, n));
}
igraphdgeevx_(&balanc, &jobvl, &jobvr, &sense, &n, &MATRIX(Acopy,0,0),
&lda, VECTOR(*myreal), VECTOR(*myimag),
vectorsleft ? &MATRIX(*vectorsleft ,0,0) : 0, &ldvl,
vectorsright ? &MATRIX(*vectorsright,0,0) : 0, &ldvr,
ilo, ihi, VECTOR(*myscale), abnrm,
rconde ? VECTOR(*rconde) : 0,
rcondv ? VECTOR(*rcondv) : 0,
VECTOR(work), &lwork, VECTOR(iwork), info);
lwork=(int) VECTOR(work)[0];
IGRAPH_CHECK(igraph_vector_resize(&work, lwork));
igraphdgeevx_(&balanc, &jobvl, &jobvr, &sense, &n, &MATRIX(Acopy,0,0),
&lda, VECTOR(*myreal), VECTOR(*myimag),
vectorsleft ? &MATRIX(*vectorsleft ,0,0) : 0, &ldvl,
vectorsright ? &MATRIX(*vectorsright,0,0) : 0, &ldvr,
ilo, ihi, VECTOR(*myscale), abnrm,
rconde ? VECTOR(*rconde) : 0,
rcondv ? VECTOR(*rcondv) : 0,
VECTOR(work), &lwork, VECTOR(iwork), info);
if (*info < 0) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeev)", IGRAPH_ELAPACK);
} else if (*info > 0) {
if (error) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeev)", IGRAPH_ELAPACK);
} else {
IGRAPH_WARNING("Cannot calculate eigenvalues (dgeev)");
}
}
if (!scale) {
igraph_vector_destroy(&vscale);
IGRAPH_FINALLY_CLEAN(1);
}
if (!valuesimag) {
igraph_vector_destroy(&vimag);
IGRAPH_FINALLY_CLEAN(1);
}
if (!valuesreal) {
igraph_vector_destroy(&vreal);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_int_destroy(&iwork);
igraph_vector_destroy(&work);
igraph_matrix_destroy(&Acopy);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int main() {
igraph_matrix_t m, m2;
igraph_vector_t v;
long int i, j, i2, j2;
igraph_real_t r1, r2;
igraph_matrix_init(&m, 4, 3);
byrow(&m);
/* igraph_matrix_e */
printf("igraph_matrix_e\n");
apply(m, printf("%i ", (int)igraph_matrix_e(&m, i, j)), printf("\n"));
/* igraph_matrix_e_ptr */
printf("igraph_matrix_e_ptr\n");
apply(m, printf("%i ", (int)igraph_matrix_e_ptr(&m, i, j)[0]), printf("\n"));
/* igraph_matrix_set */
printf("igraph_matrix_set\n");
apply(m, igraph_matrix_set(&m, i, j, i), (void) 0 );
print_matrix(&m);
apply(m, igraph_matrix_set(&m, i, j, j), (void) 0 );
print_matrix(&m);
/* igraph_matrix_fill */
printf("igraph_matrix_fill\n");
igraph_matrix_fill(&m, 42);
print_matrix(&m);
igraph_matrix_fill(&m, -42.1);
print_matrix(&m);
/* igraph_matrix_update */
printf("igraph_matrix_update\n");
igraph_matrix_init(&m2, 0, 0);
byrow(&m);
igraph_matrix_update(&m2, &m);
print_matrix(&m2);
/* igraph_matrix_rbind */
printf("igraph_matrix_rbind\n");
igraph_matrix_rbind(&m2, &m);
print_matrix(&m2);
printf("\n");
igraph_matrix_resize(&m, 0, igraph_matrix_ncol(&m2));
igraph_matrix_rbind(&m2, &m);
print_matrix(&m2);
printf("\n");
igraph_matrix_rbind(&m, &m2);
print_matrix(&m);
/* igraph_matrix_cbind */
printf("igraph_matrix_cbind\n");
igraph_matrix_resize(&m, 4, 3);
igraph_matrix_resize(&m2, 4, 2);
byrow(&m);
byrow(&m2);
igraph_matrix_cbind(&m, &m2);
print_matrix(&m);
/* igraph_matrix_swap */
printf("igraph_matrix_swap\n");
igraph_matrix_update(&m, &m2);
igraph_matrix_null(&m);
igraph_matrix_swap(&m, &m2);
print_matrix(&m);
print_matrix(&m2);
/* igraph_matrix_get_row */
/* igraph_matrix_set_row */
printf("igraph_matrix_get_row\n");
printf("igraph_matrix_set_row\n");
igraph_vector_init(&v, 0);
for (i=0; i<igraph_matrix_nrow(&m); i++) {
igraph_matrix_get_row(&m, &v, i);
igraph_matrix_set_row(&m2, &v, i);
}
print_matrix(&m2);
/* igraph_matrix_set_col */
printf("igraph_matrix_set_col\n");
igraph_matrix_null(&m2);
for (i=0; i<igraph_matrix_ncol(&m); i++) {
igraph_matrix_get_col(&m, &v, i);
igraph_matrix_set_col(&m2, &v, i);
}
print_matrix(&m2);
/* igraph_matrix_swap_rows */
printf("igraph_matrix_swap_rows\n");
igraph_matrix_swap_rows(&m2, 0, 0);
igraph_matrix_swap_rows(&m2, 0, 2);
print_matrix(&m2);
/* igraph_matrix_swap_cols */
printf("igraph_matrix_swap_cols\n");
igraph_matrix_swap_cols(&m2, 0, 0);
igraph_matrix_swap_cols(&m2, 0, 1);
print_matrix(&m2);
/* igraph_matrix_add_constant */
printf("igraph_matrix_add_constant\n");
igraph_matrix_add_constant(&m2, 0);
print_matrix(&m2);
igraph_matrix_add_constant(&m2, -1);
print_matrix(&m2);
/* igraph_matrix_add */
printf("igraph_matrix_add\n");
byrow(&m2);
byrow(&m);
igraph_matrix_add(&m2, &m);
print_matrix(&m2);
/* igraph_matrix_sub */
printf("igraph_matrix_sub\n");
igraph_matrix_sub(&m2, &m);
print_matrix(&m2);
/* igraph_matrix_mul_elements */
printf("igraph_matrix_mul_elements\n");
igraph_matrix_mul_elements(&m2, &m);
print_matrix(&m2);
/* igraph_matrix_div_elements */
printf("igraph_matrix_div_elements\n");
igraph_matrix_fill(&m, 2);
igraph_matrix_div_elements(&m2, &m);
print_matrix(&m2);
/* igraph_matrix_min */
printf("igraph_matrix_min\n");
if (igraph_matrix_min(&m2) != 0) {
return 1;
}
if (igraph_matrix_min(&m) != 2) {
return 1;
}
/* igraph_matrix_which_min */
printf("igraph_matrix_which_min\n");
igraph_matrix_which_min(&m2, &i, &j);
if (i != 0 || j != 0) { return 2; }
MATRIX(m2,0,1) = -1;
igraph_matrix_which_min(&m2, &i, &j);
if (i != 0 || j != 1) { return 2; }
MATRIX(m2,3,1) = -2;
igraph_matrix_which_min(&m2, &i, &j);
if (i != 3 || j != 1) { return 2; }
/* igraph_matrix_which_max */
printf("igraph_matrix_which_max\n");
MATRIX(m2,3,0) = 100;
igraph_matrix_which_max(&m2, &i, &j);
if (i != 3 || j != 0) { return 3; }
/* igraph_matrix_minmax */
printf("igraph_matrix_minmax\n");
igraph_matrix_minmax(&m2, &r1, &r2);
printf("%g %g\n", r1, r2);
/* igraph_matrix_which_minmax */
printf("igraph_matrix_which_minmax\n");
igraph_matrix_which_minmax(&m2, &i, &j, &i2, &j2);
if (i != 3 || j != 1 || i2 != 3 || j2 != 0) { return 4; }
/* igraph_matrix_isnull */
printf("igraph_matrix_isnull\n");
if (igraph_matrix_isnull(&m2)) { return 5; }
igraph_matrix_null(&m);
if (!igraph_matrix_isnull(&m)) { return 5; }
igraph_matrix_resize(&m2, 5, 0);
if (!igraph_matrix_isnull(&m2)) { return 5; }
/* igraph_matrix_empty */
printf("igraph_matrix_empty\n");
if (!igraph_matrix_empty(&m2)) { return 6; }
igraph_matrix_resize(&m2, 5, 5);
if (igraph_matrix_empty(&m2)) { return 6; }
/* igraph_matrix_is_symmetric */
printf("igraph_matrix_is_symmetric\n");
byrow(&m2);
if (igraph_matrix_is_symmetric(&m2)) { return 7; }
igraph_matrix_update(&m, &m2);
igraph_matrix_transpose(&m);
igraph_matrix_add(&m, &m2);
if (!igraph_matrix_is_symmetric(&m)) { return 7; }
/* igraph_matrix_prod */
printf("igraph_matrix_prod\n");
igraph_matrix_resize(&m, 3,2);
byrow(&m);
igraph_matrix_add_constant(&m, 1);
print_matrix(&m);
printf("product: %g\n", igraph_matrix_prod(&m));
/* igraph_matrix_rowsum */
printf("igraph_matrix_rowsum\n");
igraph_matrix_rowsum(&m, &v);
print_vector(&v);
/* igraph_matrix_colsum */
printf("igraph_matrix_colsum\n");
igraph_matrix_colsum(&m, &v);
print_vector(&v);
/* igraph_matrix_contains */
printf("igraph_matrix_contains\n");
if (igraph_matrix_contains(&m, 0)) { return 8; }
if (igraph_matrix_contains(&m, 6.0001)) { return 8; }
if (igraph_matrix_contains(&m, 7)) { return 8; }
if (!igraph_matrix_contains(&m, 1)) { return 8; }
if (!igraph_matrix_contains(&m, 6)) { return 8; }
/* igraph_matrix_search */
printf("igraph_matrix_search\n");
if (!igraph_matrix_search(&m, 0, 6.0, &i2, &i, &j)) { return 9; }
if (i2 != 5 || i != 2 || j != 1) { return 9; }
/* igraph_matrix_remove_row */
printf("igraph_matrix_remove_row\n");
igraph_matrix_remove_row(&m, 1);
print_matrix(&m);
igraph_matrix_resize(&m,5,4);
byrow(&m);
igraph_matrix_remove_row(&m, 4);
print_matrix(&m);
igraph_matrix_remove_row(&m, 0);
print_matrix(&m);
/* igraph_matrix_select_cols */
printf("igraph_matrix_select_cols\n");
igraph_matrix_resize(&m, 6, 5);
apply(m, igraph_matrix_set(&m, i, j, j), (void) 0 );
igraph_vector_resize(&v, 3);
VECTOR(v)[0]=0; VECTOR(v)[1]=4; VECTOR(v)[2]=2;
igraph_matrix_select_cols(&m, &m2, &v);
print_matrix(&m2);
igraph_vector_resize(&v, 1);
igraph_matrix_select_cols(&m, &m2, &v);
print_matrix(&m2);
igraph_vector_clear(&v);
igraph_matrix_select_cols(&m, &m2, &v);
if (!igraph_matrix_empty(&m2)) { return 9; }
igraph_vector_destroy(&v);
igraph_matrix_destroy(&m2);
igraph_matrix_destroy(&m);
if (IGRAPH_FINALLY_STACK_SIZE() != 0) return 10;
return 0;
}
int igraph_lapack_dgeev(const igraph_matrix_t *A,
igraph_vector_t *valuesreal,
igraph_vector_t *valuesimag,
igraph_matrix_t *vectorsleft,
igraph_matrix_t *vectorsright,
int *info) {
char jobvl= vectorsleft ? 'V' : 'N';
char jobvr= vectorsright ? 'V' : 'N';
int n=(int) igraph_matrix_nrow(A);
int lda=n, ldvl=n, ldvr=n, lwork=-1;
igraph_vector_t work;
igraph_vector_t *myreal=valuesreal, *myimag=valuesimag, vreal, vimag;
igraph_matrix_t Acopy;
int error=*info;
if (igraph_matrix_ncol(A) != n) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeev)", IGRAPH_NONSQUARE);
}
IGRAPH_CHECK(igraph_matrix_copy(&Acopy, A));
IGRAPH_FINALLY(igraph_matrix_destroy, &Acopy);
IGRAPH_VECTOR_INIT_FINALLY(&work, 1);
if (!valuesreal) {
IGRAPH_VECTOR_INIT_FINALLY(&vreal, n);
myreal=&vreal;
} else {
IGRAPH_CHECK(igraph_vector_resize(myreal, n));
}
if (!valuesimag) {
IGRAPH_VECTOR_INIT_FINALLY(&vimag, n);
myimag=&vimag;
} else {
IGRAPH_CHECK(igraph_vector_resize(myimag, n));
}
if (vectorsleft) {
IGRAPH_CHECK(igraph_matrix_resize(vectorsleft, n, n));
}
if (vectorsright) {
IGRAPH_CHECK(igraph_matrix_resize(vectorsright, n, n));
}
igraphdgeev_(&jobvl, &jobvr, &n, &MATRIX(Acopy,0,0), &lda,
VECTOR(*myreal), VECTOR(*myimag),
vectorsleft ? &MATRIX(*vectorsleft ,0,0) : 0, &ldvl,
vectorsright ? &MATRIX(*vectorsright,0,0) : 0, &ldvr,
VECTOR(work), &lwork, info);
lwork=(int) VECTOR(work)[0];
IGRAPH_CHECK(igraph_vector_resize(&work, lwork));
igraphdgeev_(&jobvl, &jobvr, &n, &MATRIX(Acopy,0,0), &lda,
VECTOR(*myreal), VECTOR(*myimag),
vectorsleft ? &MATRIX(*vectorsleft ,0,0) : 0, &ldvl,
vectorsright ? &MATRIX(*vectorsright,0,0) : 0, &ldvr,
VECTOR(work), &lwork, info);
if (*info < 0) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeev)", IGRAPH_ELAPACK);
} else if (*info > 0) {
if (error) {
IGRAPH_ERROR("Cannot calculate eigenvalues (dgeev)", IGRAPH_ELAPACK);
} else {
IGRAPH_WARNING("Cannot calculate eigenvalues (dgeev)");
}
}
if (!valuesimag) {
igraph_vector_destroy(&vimag);
IGRAPH_FINALLY_CLEAN(1);
}
if (!valuesreal) {
igraph_vector_destroy(&vreal);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_destroy(&work);
igraph_matrix_destroy(&Acopy);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}
int igraph_lapack_dsyevr(const igraph_matrix_t *A,
igraph_lapack_dsyev_which_t which,
igraph_real_t vl, igraph_real_t vu, int vestimate,
int il, int iu, igraph_real_t abstol,
igraph_vector_t *values, igraph_matrix_t *vectors,
igraph_vector_int_t *support) {
igraph_matrix_t Acopy;
char jobz = vectors ? 'V' : 'N', range, uplo='U';
int n=(int) igraph_matrix_nrow(A), lda=n, ldz=n;
int m, info;
igraph_vector_t *myvalues=values, vvalues;
igraph_vector_int_t *mysupport=support, vsupport;
igraph_vector_t work;
igraph_vector_int_t iwork;
int lwork=-1, liwork=-1;
if (n != igraph_matrix_ncol(A)) {
IGRAPH_ERROR("Cannot find eigenvalues/vectors", IGRAPH_NONSQUARE);
}
if (which==IGRAPH_LAPACK_DSYEV_INTERVAL &&
(vestimate < 1 || vestimate > n)) {
IGRAPH_ERROR("Estimated (upper bound) number of eigenvalues must be "
"between 1 and n", IGRAPH_EINVAL);
}
if (which==IGRAPH_LAPACK_DSYEV_SELECT && iu-il < 0) {
IGRAPH_ERROR("Invalid 'il' and/or 'iu' values", IGRAPH_EINVAL);
}
IGRAPH_CHECK(igraph_matrix_copy(&Acopy, A));
IGRAPH_FINALLY(igraph_matrix_destroy, &Acopy);
IGRAPH_VECTOR_INIT_FINALLY(&work, 1);
IGRAPH_CHECK(igraph_vector_int_init(&iwork, 1));
IGRAPH_FINALLY(igraph_vector_int_destroy, &iwork);
if (!values) {
IGRAPH_VECTOR_INIT_FINALLY(&vvalues, 0);
myvalues=&vvalues;
}
if (!support) {
IGRAPH_CHECK(igraph_vector_int_init(&vsupport, 0));
IGRAPH_FINALLY(igraph_vector_int_destroy, &vsupport);
mysupport=&vsupport;
}
switch (which) {
case IGRAPH_LAPACK_DSYEV_ALL:
range = 'A';
IGRAPH_CHECK(igraph_vector_resize(myvalues, n));
IGRAPH_CHECK(igraph_vector_int_resize(mysupport, 2*n));
if (vectors) { IGRAPH_CHECK(igraph_matrix_resize(vectors, n, n)); }
break;
case IGRAPH_LAPACK_DSYEV_INTERVAL:
range = 'V';
IGRAPH_CHECK(igraph_vector_resize(myvalues, vestimate));
IGRAPH_CHECK(igraph_vector_int_resize(mysupport, 2*vestimate));
if (vectors) { IGRAPH_CHECK(igraph_matrix_resize(vectors,n, vestimate)); }
break;
case IGRAPH_LAPACK_DSYEV_SELECT:
range = 'I';
IGRAPH_CHECK(igraph_vector_resize(myvalues, iu-il+1));
IGRAPH_CHECK(igraph_vector_int_resize(mysupport, 2*(iu-il+1)));
if (vectors) { IGRAPH_CHECK(igraph_matrix_resize(vectors, n, iu-il+1)); }
break;
}
igraphdsyevr_(&jobz, &range, &uplo, &n, &MATRIX(Acopy,0,0), &lda,
&vl, &vu, &il, &iu, &abstol, &m, VECTOR(*myvalues),
vectors ? &MATRIX(*vectors,0,0) : 0, &ldz, VECTOR(*mysupport),
VECTOR(work), &lwork, VECTOR(iwork), &liwork, &info);
lwork=(int) VECTOR(work)[0];
liwork=VECTOR(iwork)[0];
IGRAPH_CHECK(igraph_vector_resize(&work, lwork));
IGRAPH_CHECK(igraph_vector_int_resize(&iwork, liwork));
igraphdsyevr_(&jobz, &range, &uplo, &n, &MATRIX(Acopy,0,0), &lda,
&vl, &vu, &il, &iu, &abstol, &m, VECTOR(*myvalues),
vectors ? &MATRIX(*vectors,0,0) : 0, &ldz, VECTOR(*mysupport),
VECTOR(work), &lwork, VECTOR(iwork), &liwork, &info);
if (values) {
IGRAPH_CHECK(igraph_vector_resize(values, m));
}
if (vectors) {
IGRAPH_CHECK(igraph_matrix_resize(vectors, n, m));
}
if (support) {
IGRAPH_CHECK(igraph_vector_int_resize(support, m));
}
if (!support) {
igraph_vector_int_destroy(&vsupport);
IGRAPH_FINALLY_CLEAN(1);
}
if (!values) {
igraph_vector_destroy(&vvalues);
IGRAPH_FINALLY_CLEAN(1);
}
igraph_vector_int_destroy(&iwork);
igraph_vector_destroy(&work);
igraph_matrix_destroy(&Acopy);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
int igraph_lapack_dgesv(igraph_matrix_t *a, igraph_vector_int_t *ipiv,
igraph_matrix_t *b, int *info) {
int n=(int) igraph_matrix_nrow(a);
int nrhs=(int) igraph_matrix_ncol(b);
int lda= n > 0 ? n : 1;
int ldb= n > 0 ? n : 1;
igraph_vector_int_t *myipiv=ipiv, vipiv;
if (n != igraph_matrix_ncol(a)) {
IGRAPH_ERROR("Cannot LU solve matrix", IGRAPH_NONSQUARE);
}
if (n != igraph_matrix_nrow(b)) {
IGRAPH_ERROR("Cannot LU solve matrix, RHS of wrong size", IGRAPH_EINVAL);
}
if (!ipiv) {
IGRAPH_CHECK(igraph_vector_int_init(&vipiv, n));
IGRAPH_FINALLY(igraph_vector_int_destroy, &vipiv);
myipiv=&vipiv;
}
igraphdgesv_(&n, &nrhs, VECTOR(a->data), &lda, VECTOR(*myipiv),
VECTOR(b->data), &ldb, info);
if (*info > 0) {
IGRAPH_WARNING("LU: factor is exactly singular");
} else if (*info < 0) {
switch(*info) {
case -1:
IGRAPH_ERROR("Invalid number of rows/column", IGRAPH_ELAPACK);
break;
case -2:
IGRAPH_ERROR("Invalid number of RHS vectors", IGRAPH_ELAPACK);
break;
case -3:
IGRAPH_ERROR("Invalid input matrix", IGRAPH_ELAPACK);
break;
case -4:
IGRAPH_ERROR("Invalid LDA parameter", IGRAPH_ELAPACK);
break;
case -5:
IGRAPH_ERROR("Invalid pivot vector", IGRAPH_ELAPACK);
break;
case -6:
IGRAPH_ERROR("Invalid RHS matrix", IGRAPH_ELAPACK);
break;
case -7:
IGRAPH_ERROR("Invalid LDB parameter", IGRAPH_ELAPACK);
break;
case -8:
IGRAPH_ERROR("Invalid info argument", IGRAPH_ELAPACK);
break;
default:
IGRAPH_ERROR("Unknown LAPACK error", IGRAPH_ELAPACK);
break;
}
}
if (!ipiv) {
igraph_vector_int_destroy(&vipiv);
IGRAPH_FINALLY_CLEAN(1);
}
return 0;
}
long int Matrix::ncol() const noexcept { return igraph_matrix_ncol(ptr()); }
/**
* \ingroup nongraph
* \function igraph_convex_hull
* \brief Determines the convex hull of a given set of points in the 2D plane
*
* </para><para>
* The convex hull is determined by the Graham scan algorithm.
* See the following reference for details:
*
* </para><para>
* Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford
* Stein. Introduction to Algorithms, Second Edition. MIT Press and
* McGraw-Hill, 2001. ISBN 0262032937. Pages 949-955 of section 33.3:
* Finding the convex hull.
*
* \param data vector containing the coordinates. The length of the
* vector must be even, since it contains X-Y coordinate pairs.
* \param resverts the vector containing the result, e.g. the vector of
* vertex indices used as the corners of the convex hull. Supply
* \c NULL here if you are only interested in the coordinates of
* the convex hull corners.
* \param rescoords the matrix containing the coordinates of the selected
* corner vertices. Supply \c NULL here if you are only interested in
* the vertex indices.
* \return Error code:
* \c IGRAPH_ENOMEM: not enough memory
*
* Time complexity: O(n log(n)) where n is the number of vertices
*/
int igraph_convex_hull(const igraph_matrix_t *data, igraph_vector_t *resverts,
igraph_matrix_t *rescoords) {
igraph_integer_t no_of_nodes;
long int i, pivot_idx=0, last_idx, before_last_idx, next_idx, j;
igraph_real_t* angles;
igraph_vector_t stack;
igraph_indheap_t order;
igraph_real_t px, py, cp;
no_of_nodes=igraph_matrix_nrow(data);
if (igraph_matrix_ncol(data) != 2) {
IGRAPH_ERROR("matrix must have 2 columns", IGRAPH_EINVAL);
}
if (no_of_nodes == 0) {
if (resverts != 0) {
IGRAPH_CHECK(igraph_vector_resize(resverts, 0));
}
if (rescoords != 0) {
IGRAPH_CHECK(igraph_matrix_resize(rescoords, 0, 2));
}
/**************************** this is an exit here *********/
return 0;
}
angles=igraph_Calloc(no_of_nodes, igraph_real_t);
if (!angles) IGRAPH_ERROR("not enough memory for angle array", IGRAPH_ENOMEM);
IGRAPH_FINALLY(free, angles);
IGRAPH_VECTOR_INIT_FINALLY(&stack, 0);
/* Search for the pivot vertex */
for (i=1; i<no_of_nodes; i++) {
if (MATRIX(*data, i, 1)<MATRIX(*data, pivot_idx, 1))
pivot_idx=i;
else if (MATRIX(*data, i, 1) == MATRIX(*data, pivot_idx, 1) &&
MATRIX(*data, i, 0) < MATRIX(*data, pivot_idx, 0))
pivot_idx=i;
}
px=MATRIX(*data, pivot_idx, 0);
py=MATRIX(*data, pivot_idx, 1);
/* Create angle array */
for (i=0; i<no_of_nodes; i++) {
if (i == pivot_idx) {
/* We can't calculate the angle of the pivot point with itself,
* so we use 10 here. This way, after sorting the angle vector,
* the pivot point will always be the first one, since the range
* of atan2 is -3.14..3.14 */
angles[i] = 10;
} else {
angles[i] = atan2(MATRIX(*data, i, 1)-py,
MATRIX(*data, i, 0)-px);
}
}
IGRAPH_CHECK(igraph_indheap_init_array(&order, angles, no_of_nodes));
IGRAPH_FINALLY(igraph_indheap_destroy, &order);
igraph_Free(angles);
IGRAPH_FINALLY_CLEAN(1);
if (no_of_nodes == 1) {
IGRAPH_CHECK(igraph_vector_push_back(&stack, 0));
igraph_indheap_delete_max(&order);
} else {
/* Do the trick */
IGRAPH_CHECK(igraph_vector_push_back(&stack, igraph_indheap_max_index(&order)-1));
igraph_indheap_delete_max(&order);
IGRAPH_CHECK(igraph_vector_push_back(&stack, igraph_indheap_max_index(&order)-1));
igraph_indheap_delete_max(&order);
j=2;
while (!igraph_indheap_empty(&order)) {
/* Determine whether we are at a left or right turn */
last_idx=VECTOR(stack)[j-1];
before_last_idx=VECTOR(stack)[j-2];
next_idx=(long)igraph_indheap_max_index(&order)-1;
igraph_indheap_delete_max(&order);
cp=(MATRIX(*data, last_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, next_idx, 1)-MATRIX(*data, before_last_idx, 1))-
(MATRIX(*data, next_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, last_idx, 1)-MATRIX(*data, before_last_idx, 1));
/*
printf("B L N cp: %d, %d, %d, %f [", before_last_idx, last_idx, next_idx, (float)cp);
for (k=0; k<j; k++) printf("%ld ", (long)VECTOR(stack)[k]);
printf("]\n");
*/
if (cp == 0) {
/* The last three points are collinear. Replace the last one in
* the stack to the newest one */
VECTOR(stack)[j-1]=next_idx;
} else if (cp < 0) {
/* We are turning into the right direction */
IGRAPH_CHECK(igraph_vector_push_back(&stack, next_idx));
j++;
} else {
/* No, skip back until we're okay */
while (cp >= 0 && j > 2) {
igraph_vector_pop_back(&stack);
j--;
last_idx=VECTOR(stack)[j-1];
before_last_idx=VECTOR(stack)[j-2];
cp=(MATRIX(*data, last_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, next_idx, 1)-MATRIX(*data, before_last_idx, 1))-
(MATRIX(*data, next_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, last_idx, 1)-MATRIX(*data, before_last_idx, 1));
}
IGRAPH_CHECK(igraph_vector_push_back(&stack, next_idx));
j++;
}
}
}
/* Create result vector */
if (resverts != 0) {
igraph_vector_clear(resverts);
IGRAPH_CHECK(igraph_vector_append(resverts, &stack));
}
if (rescoords != 0) {
igraph_matrix_select_rows(data, rescoords, &stack);
}
/* Free everything */
igraph_vector_destroy(&stack);
igraph_indheap_destroy(&order);
IGRAPH_FINALLY_CLEAN(2);
return 0;
}
int igraph_incidence(igraph_t *graph, igraph_vector_bool_t *types,
const igraph_matrix_t *incidence,
igraph_bool_t directed,
igraph_neimode_t mode, igraph_bool_t multiple) {
igraph_integer_t n1=(igraph_integer_t) igraph_matrix_nrow(incidence);
igraph_integer_t n2=(igraph_integer_t) igraph_matrix_ncol(incidence);
igraph_integer_t no_of_nodes=n1+n2;
igraph_vector_t edges;
long int i, j, k;
IGRAPH_VECTOR_INIT_FINALLY(&edges, 0);
if (multiple) {
for (i=0; i<n1; i++) {
for (j=0; j<n2; j++) {
long int elem=(long int) MATRIX(*incidence, i, j);
long int from, to;
if (!elem) { continue; }
if (mode == IGRAPH_IN) {
from=n1+j;
to=i;
} else {
from=i;
to=n1+j;
}
if (mode != IGRAPH_ALL || !directed) {
for (k=0; k<elem; k++) {
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
}
} else {
for (k=0; k<elem; k++) {
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
}
}
}
}
} else {
for (i=0; i<n1; i++) {
for (j=0; j<n2; j++) {
long int from, to;
if (MATRIX(*incidence, i, j) != 0) {
if (mode == IGRAPH_IN) {
from=n1+j;
to=i;
} else {
from=i;
to=n1+j;
}
if (mode != IGRAPH_ALL || !directed) {
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
} else {
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
IGRAPH_CHECK(igraph_vector_push_back(&edges, to));
IGRAPH_CHECK(igraph_vector_push_back(&edges, from));
}
}
}
}
}
IGRAPH_CHECK(igraph_create(graph, &edges, no_of_nodes, directed));
igraph_vector_destroy(&edges);
IGRAPH_FINALLY_CLEAN(1);
IGRAPH_FINALLY(igraph_destroy, graph);
if (types) {
IGRAPH_CHECK(igraph_vector_bool_resize(types, no_of_nodes));
igraph_vector_bool_null(types);
for (i=n1; i<no_of_nodes; i++) {
VECTOR(*types)[i] = 1;
}
}
IGRAPH_FINALLY_CLEAN(1);
return 0;
}
int igraph_lapack_dgehrd(const igraph_matrix_t *A,
int ilo, int ihi,
igraph_matrix_t *result) {
int n=(int) igraph_matrix_nrow(A);
int lda=n;
int lwork=-1;
igraph_vector_t work;
igraph_real_t optwork;
igraph_vector_t tau;
igraph_matrix_t Acopy;
int info=0;
int i;
if (igraph_matrix_ncol(A) != n) {
IGRAPH_ERROR("Hessenberg reduction failed", IGRAPH_NONSQUARE);
}
if (ilo < 1 || ihi > n || ilo > ihi) {
IGRAPH_ERROR("Invalid `ilo' and/or `ihi'", IGRAPH_EINVAL);
}
if (n <= 1) {
IGRAPH_CHECK(igraph_matrix_update(result, A));
return 0;
}
IGRAPH_CHECK(igraph_matrix_copy(&Acopy, A));
IGRAPH_FINALLY(igraph_matrix_destroy, &Acopy);
IGRAPH_VECTOR_INIT_FINALLY(&tau, n-1);
igraphdgehrd_(&n, &ilo, &ihi, &MATRIX(Acopy, 0, 0), &lda, VECTOR(tau),
&optwork, &lwork, &info);
if (info != 0) {
IGRAPH_ERROR("Internal Hessenberg transformation error",
IGRAPH_EINTERNAL);
}
lwork=(int) optwork;
IGRAPH_VECTOR_INIT_FINALLY(&work, lwork);
igraphdgehrd_(&n, &ilo, &ihi, &MATRIX(Acopy, 0, 0), &lda, VECTOR(tau),
VECTOR(work), &lwork, &info);
if (info != 0) {
IGRAPH_ERROR("Internal Hessenberg transformation error",
IGRAPH_EINTERNAL);
}
igraph_vector_destroy(&work);
igraph_vector_destroy(&tau);
IGRAPH_FINALLY_CLEAN(2);
IGRAPH_CHECK(igraph_matrix_update(result, &Acopy));
igraph_matrix_destroy(&Acopy);
IGRAPH_FINALLY_CLEAN(1);
for (i=0; i<n-2; i++) {
int j;
for (j=i+2; j<n; j++) {
MATRIX(*result, j, i) = 0.0;
}
}
return 0;
}
/**
* \ingroup nongraph
* \function igraph_convex_hull
* \brief Determines the convex hull of a given set of points in the 2D plane
*
* </para><para>
* The convex hull is determined by the Graham scan algorithm.
* See the following reference for details:
*
* </para><para>
* Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford
* Stein. Introduction to Algorithms, Second Edition. MIT Press and
* McGraw-Hill, 2001. ISBN 0262032937. Pages 949-955 of section 33.3:
* Finding the convex hull.
*
* \param data vector containing the coordinates. The length of the
* vector must be even, since it contains X-Y coordinate pairs.
* \param resverts the vector containing the result, e.g. the vector of
* vertex indices used as the corners of the convex hull. Supply
* \c NULL here if you are only interested in the coordinates of
* the convex hull corners.
* \param rescoords the matrix containing the coordinates of the selected
* corner vertices. Supply \c NULL here if you are only interested in
* the vertex indices.
* \return Error code:
* \c IGRAPH_ENOMEM: not enough memory
*
* Time complexity: O(n log(n)) where n is the number of vertices
*
* \example examples/simple/igraph_convex_hull.c
*/
int igraph_convex_hull(const igraph_matrix_t *data, igraph_vector_t *resverts,
igraph_matrix_t *rescoords) {
igraph_integer_t no_of_nodes;
long int i, pivot_idx=0, last_idx, before_last_idx, next_idx, j;
igraph_vector_t angles, stack, order;
igraph_real_t px, py, cp;
no_of_nodes=(igraph_integer_t) igraph_matrix_nrow(data);
if (igraph_matrix_ncol(data) != 2) {
IGRAPH_ERROR("matrix must have 2 columns", IGRAPH_EINVAL);
}
if (no_of_nodes == 0) {
if (resverts != 0) {
IGRAPH_CHECK(igraph_vector_resize(resverts, 0));
}
if (rescoords != 0) {
IGRAPH_CHECK(igraph_matrix_resize(rescoords, 0, 2));
}
/**************************** this is an exit here *********/
return 0;
}
IGRAPH_VECTOR_INIT_FINALLY(&angles, no_of_nodes);
IGRAPH_VECTOR_INIT_FINALLY(&stack, 0);
/* Search for the pivot vertex */
for (i=1; i<no_of_nodes; i++) {
if (MATRIX(*data, i, 1)<MATRIX(*data, pivot_idx, 1))
pivot_idx=i;
else if (MATRIX(*data, i, 1) == MATRIX(*data, pivot_idx, 1) &&
MATRIX(*data, i, 0) < MATRIX(*data, pivot_idx, 0))
pivot_idx=i;
}
px=MATRIX(*data, pivot_idx, 0);
py=MATRIX(*data, pivot_idx, 1);
/* Create angle array */
for (i=0; i<no_of_nodes; i++) {
if (i == pivot_idx) {
/* We can't calculate the angle of the pivot point with itself,
* so we use 10 here. This way, after sorting the angle vector,
* the pivot point will always be the first one, since the range
* of atan2 is -3.14..3.14 */
VECTOR(angles)[i] = 10;
} else {
VECTOR(angles)[i] = atan2(MATRIX(*data, i, 1)-py, MATRIX(*data, i, 0)-px);
}
}
/* Sort points by angles */
IGRAPH_VECTOR_INIT_FINALLY(&order, no_of_nodes);
IGRAPH_CHECK(igraph_vector_qsort_ind(&angles, &order, 0));
/* Check if two points have the same angle. If so, keep only the point that
* is farthest from the pivot */
j = 0;
last_idx = (long int) VECTOR(order)[0];
pivot_idx = (long int) VECTOR(order)[no_of_nodes - 1];
for (i=1; i < no_of_nodes; i++) {
next_idx = (long int) VECTOR(order)[i];
if (VECTOR(angles)[last_idx] == VECTOR(angles)[next_idx]) {
/* Keep the vertex that is farther from the pivot, drop the one that is
* closer */
px = pow(MATRIX(*data, last_idx, 0) - MATRIX(*data, pivot_idx, 0), 2) +
pow(MATRIX(*data, last_idx, 1) - MATRIX(*data, pivot_idx, 1), 2);
py = pow(MATRIX(*data, next_idx, 0) - MATRIX(*data, pivot_idx, 0), 2) +
pow(MATRIX(*data, next_idx, 1) - MATRIX(*data, pivot_idx, 1), 2);
if (px > py) {
VECTOR(order)[i] = -1;
} else {
VECTOR(order)[j] = -1;
last_idx = next_idx;
j = i;
}
} else {
last_idx = next_idx;
j = i;
}
}
j=0;
last_idx=-1;
before_last_idx=-1;
while (!igraph_vector_empty(&order)) {
next_idx=(long int)VECTOR(order)[igraph_vector_size(&order) - 1];
if (next_idx < 0) {
/* This vertex should be skipped; was excluded in an earlier step */
igraph_vector_pop_back(&order);
continue;
}
/* Determine whether we are at a left or right turn */
if (j < 2) {
/* Pretend that we are turning into the right direction if we have less
* than two items in the stack */
cp=-1;
} else {
cp=(MATRIX(*data, last_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, next_idx, 1)-MATRIX(*data, before_last_idx, 1))-
(MATRIX(*data, next_idx, 0)-MATRIX(*data, before_last_idx, 0))*
(MATRIX(*data, last_idx, 1)-MATRIX(*data, before_last_idx, 1));
}
/*
printf("B L N cp: %ld, %ld, %ld, %f [", before_last_idx, last_idx, next_idx, (float)cp);
for (int k=0; k<j; k++) printf("%ld ", (long)VECTOR(stack)[k]);
printf("]\n");
*/
if (cp < 0) {
/* We are turning into the right direction */
igraph_vector_pop_back(&order);
IGRAPH_CHECK(igraph_vector_push_back(&stack, next_idx));
before_last_idx = last_idx;
last_idx = next_idx;
j++;
} else {
/* No, skip back and try again in the next iteration */
igraph_vector_pop_back(&stack);
j--;
last_idx = before_last_idx;
before_last_idx = (j >= 2) ? (long int) VECTOR(stack)[j-2] : -1;
}
}
/* Create result vector */
if (resverts != 0) {
igraph_vector_clear(resverts);
IGRAPH_CHECK(igraph_vector_append(resverts, &stack));
}
if (rescoords != 0) {
igraph_matrix_select_rows(data, rescoords, &stack);
}
/* Free everything */
igraph_vector_destroy(&order);
igraph_vector_destroy(&stack);
igraph_vector_destroy(&angles);
IGRAPH_FINALLY_CLEAN(3);
return 0;
}
/*__________________________________________________________________________ MAIN CYCLE (FLTK CYCLE) ____*/
void mainidle_cb(void*){ //this routine updates the program.
//thus, it computes the EVOLUTION
double shooted;
double dens, err;
double totdens, toterr, totimerr;
char s[100];
// ---- running controls AND PRINTING
if(
(amstepping==0 && runningcontrol==1 && graphisloaded==1 && ticks<=maxtime ) ||
(amstepping==1 && runningcontrol==1 && graphisloaded==1 && ticks<=maxtime && tickstep<=step-1)
)
{
Evolution(deltat);
//PRINTS
if((int)printdatabutton->value()==1){
//if have steady state
if(usesteady==1){
igraph_matrix_t activation;
igraph_matrix_init(&activation,nodesnumber,totrun);
igraph_matrix_null(&activation);
igraph_vector_t correlation;
igraph_vector_init(&correlation,(nodesnumber*nodesnumber)); igraph_vector_null(&correlation);
fprintf(output1,"%i ", ticks);
fprintf(output2,"%i ", ticks);
fprintf(output5,"%i ", ticks);
fprintf(output6,"%i ", ticks);
totdens=0; toterr=0;
for(int i=0;i<nodesnumber;++i){
shooted=0;
dens=0;
err=0;
for(int j=0; j<totrun; ++j){
dens=dens+MATRIX(density,i,j);
err=err+((VECTOR(statstate)[i]-MATRIX(density,i,j))*(VECTOR(statstate)[i]-MATRIX(density,i,j)));
shooted=shooted+MATRIX(loss,i,j);
if(MATRIX(loss,i,j)!=0){++MATRIX(activation,i,j);}
}
dens=dens/totrun;
err=sqrt(err)/totrun;
shooted=shooted/totrun;
totdens=totdens+dens;
toterr=toterr+err;
fprintf(output1,"%f ",dens);
fprintf(output2,"%f ",err);
fprintf(output5,"%f ",shooted);
}
totdens=totdens/nodesnumber;
toterr=toterr/nodesnumber;
fprintf(output1,"%f ",totdens);
fprintf(output2,"%f ",toterr);
// printf("\n\n ACTIVATION MATRIX \n \n"); print_matrix_ur(&activation,stdout); printf("\n\n");
// ---- CORRELATION ---
igraph_vector_t meanactivation;
igraph_vector_init(&meanactivation,nodesnumber);
igraph_vector_null(&meanactivation);
//calculate mean activation
for (int j=0; j<totrun; ++j) {
for (int i=0; i<nodesnumber; ++i) {
VECTOR(meanactivation)[i]=VECTOR(meanactivation)[i]+MATRIX(activation,i,j);
}
}
igraph_vector_scale(&meanactivation,1./totrun);
//calculate actual correlation
for (int x=0; x<nodesnumber ; ++x) {
for(int y=0; y<nodesnumber; ++y){
double prod=0;
for (int j=0; j<totrun; ++j) {
prod=prod+ ( MATRIX(activation,x,j)*MATRIX(activation,y,j) );
}
prod=prod/totrun;
VECTOR(correlation)[(x*nodesnumber+y)] = prod - (VECTOR(meanactivation)[x]*VECTOR(meanactivation)[y]);
}
}
igraph_vector_destroy(&meanactivation);
for (int i=0; i<(nodesnumber*nodesnumber); ++i) {
fprintf(output6,"%f ",VECTOR(correlation)[i]);
}
//calculate error on run
igraph_matrix_t distl1; igraph_matrix_t distimel1;
igraph_matrix_init(&distl1,nodesnumber,totrun); igraph_matrix_init(&distimel1,nodesnumber,totrun);
igraph_matrix_null(&distl1); igraph_matrix_null(&distimel1);
igraph_vector_t rundistl1; igraph_vector_t rundistimel1;
igraph_vector_init(&rundistl1,totrun); igraph_vector_init(&rundistimel1,totrun);
igraph_vector_null(&rundistl1); igraph_vector_null(&rundistimel1);
toterr=0; totimerr=0;
//for every run
for(int j=0;j<totrun;++j){
//i evaluate the distance between the state and the stationary state (toterr) and the distance between old and new density (totimerr)
for(int i=0; i<nodesnumber; ++i)
{
//L1 DISTANCE WRT STATSTATE & DENSITY
MATRIX(distl1,i,j)=fabs(VECTOR(statstate)[i]-MATRIX(density,i,j));
//L1 DISTANCE WRT OLD DENSITY & DENSITY
MATRIX(distimel1,i,j)=fabs(MATRIX(densityold,i,j)-MATRIX(density,i,j));
}
}
igraph_matrix_rowsum(&distl1,&rundistl1); igraph_matrix_rowsum(&distimel1,&rundistimel1);
igraph_vector_scale(&rundistl1,(1./nodesnumber)); igraph_vector_scale(&rundistimel1,(1./nodesnumber));
toterr= (double)( igraph_vector_sum(&rundistl1) ) / (double)totrun ;
totimerr= (double)( igraph_vector_sum(&rundistimel1)) / (double)totrun;
igraph_vector_destroy(&rundistl1); igraph_vector_destroy(&rundistimel1);
igraph_matrix_destroy(&distl1); igraph_matrix_destroy(&distimel1);
fprintf(output2,"%f %f",toterr, totimerr);
fprintf(output1,"\n");
fprintf(output2,"\n");
fprintf(output5,"\n");
fprintf(output6,"\n");
//if i have BRIDGES ("clustered" graph), I print the traffic on the BRIDGES, using "output3" file
if(isclustered==1){
//for each bridge
fprintf(output3,"%i ",ticks);
for(int nbri=0; nbri<igraph_matrix_ncol(&bridgeslinks); ++nbri){
for(int i=0; i<igraph_matrix_nrow(&bridgeslinks);++i){
double tfl=0;
for(int j=0; j<totrun; ++j){
int beid;
beid=(int)MATRIX(bridgeslinks,i,nbri);
tfl=tfl+MATRIX(flux,beid,j);
}
fprintf(output3,"%f ",tfl);
}
}
fprintf(output3,"\n");
}
igraph_matrix_destroy(&activation);
igraph_vector_destroy(&correlation);
}
//if i HAVENT STEADY STATE
else {
fprintf(output1,"%i ", ticks);
fprintf(output5,"%i ", ticks);
for(int i=0;i<nodesnumber;++i){
shooted=0;
dens=0;
for(int j=0; j<totrun; ++j){
dens=dens+MATRIX(density,i,j);
shooted=shooted+MATRIX(loss,i,j);
}
dens=dens/totrun;
shooted=shooted/totrun;
fprintf(output1,"%f " ,dens);
fprintf(output5,"%f " ,shooted);
}
fprintf(output1,"\n");
fprintf(output5,"\n");
}
}
}
if((ticks==maxtime || tickstep==step) && runningcontrol==1){
run();
}
// ---- no graph loaded
if(graphisloaded==0 && rewrite==1) {
runbutton->deactivate();
sprintf(s,"No\nnetwork\nloaded");
databuff->text(s);
}
// ---- graph loaded
else {
runbutton->activate();
if(islattice==1 && rewrite==1){
if(istoro==1){
sprintf(s,"Nodes=%i\nToroidal\nLattice\n%iD Side=%i",nodesnumber, latticedim, latticeside);
}
else{
sprintf(s,"Nodes=%i\nLattice\n%iD Side=%i",nodesnumber, latticedim, latticeside);
}
databuff->text(s);
}
else if(rewrite==1){
sprintf(s,"Nodes=%i",nodesnumber);
databuff->text(s);
}
}
//have path
if(havepath==1 && rewrite==1){pathbuff->text(path); }
else if(havepath==0 && rewrite==1){pathbuff->text("No Path");}
if(error==1 && rewrite==1){
sprintf(s,errorstring);
databuff->text(s);
}
if (ticks<=maxtime){
scene->redraw();
datascene->redraw();
}
rewrite=0;
//Fl::repeat_timeout(1.0, mainidle_cb);
}
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;
}