int
main (void) {
test_new ();
test_import ();
test_split ();
test_replace ();
test_copy ();
test_cut ();
test_search ();
test_tail_head ();
return 0;
}
/*
* The mex function runs a max-flow min-cut problem.
*/
void mexFunction(int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[])
{
mbglIndex i,j,k;
mbglIndex mrows, ncols;
mbglIndex n,nz;
/* sparse matrix */
mwIndex *A_row, *A_col;
double *A_val;
/* source/sink */
mbglIndex u, v;
/* algorithm name */
char *algname;
/* flow matrix connectivity */
mbglIndex *pi_flow, *j_flow;
/* capacity and residual structures */
int *cap, *res;
/* reverse edge map */
mbglIndex *rev_edge_map;
/* result */
int flow;
/* output */
double *pflowval;
double *pmincut;
double *pri;
double *prj;
double *prv;
/*
* The current calling pattern is
* matching_mex(A,verify,initial_match_name,augmenting_path_name)
*/
const mxArray* arg_matrix;
const mxArray* arg_source;
const mxArray* arg_sink;
const mxArray* arg_algname;
int required_arguments = 4;
if (nrhs != required_arguments) {
mexErrMsgIdAndTxt("matlab_bgl:invalidMexArgument",
"the function requires %i arguments, not %i\n",
required_arguments, nrhs);
}
arg_matrix = prhs[0];
arg_source = prhs[1];
arg_sink = prhs[2];
arg_algname = prhs[3];
u = (mbglIndex)load_scalar_arg(arg_source,1);
v = (mbglIndex)load_scalar_arg(arg_sink,2);
algname = load_string_arg(arg_algname,3);
/* The first input must be a sparse matrix. */
mrows = mxGetM(prhs[0]);
ncols = mxGetN(prhs[0]);
if (mrows != ncols ||
!mxIsSparse(prhs[0]) ||
!mxIsDouble(prhs[0]) ||
mxIsComplex(prhs[0]))
{
mexErrMsgIdAndTxt("matlab_bgl:invalidMexArgument",
"the matrix must be sparse, square, and double valued");
}
n = mrows;
/* Get the sparse matrix */
A_val = mxGetPr(prhs[0]);
A_row = mxGetIr(prhs[0]);
A_col = mxGetJc(prhs[0]);
nz = A_col[n];
/* Quick input check */
if (u > n || u < 1) {
mexErrMsgIdAndTxt("matlab_bgl:invalidMexArgument",
"invalid source vertex: %i\n", u);
}
if (v > n || v < 1) {
mexErrMsgIdAndTxt("matlab_bgl:invalidMexArgument",
"invalid sink vertex: %i\n", v);
}
u = u-1;
v = v-1;
/* build flow connectivity structure */
build_matrix(n,A_row,A_col,A_val,
&pi_flow, &j_flow, &cap, &rev_edge_map);
/* allocate the residual map */
res = mxCalloc(sizeof(int),pi_flow[n]);
/*i = 0;
for (k=0; k < pi_flow[n]; k++)
{
// get the correct row
while (k >= pi_flow[i+1]) { ++i; }
mexPrintf("(%i,%i) (%i,%i)\n", i,j_flow[k],cap[k],res[k]);
}*/
/* mexPrintf("Calling flow (%i,%i)...\n", u, v); */
#ifdef _DEBUG
mexPrintf("max_flow(%s)...", algname);
#endif
if (strcmp(algname,"push_relabel") == 0) {
push_relabel_max_flow(n,j_flow,pi_flow,
u,v,cap,res,rev_edge_map,&flow);
} else if (strcmp(algname, "edmunds_karp") == 0) {
edmonds_karp_max_flow(n,j_flow,pi_flow,
u,v,cap,res,rev_edge_map,&flow);
} else if (strcmp(algname, "kolmogorov") == 0) {
boykov_kolmogorov_max_flow(n,j_flow,pi_flow,
u,v,cap,res,rev_edge_map,&flow);
} else {
mexErrMsgIdAndTxt("matlab_bgl:invalidMexArgument",
"algname option %s is invalid\n",
algname);
}
#ifdef _DEBUG
mexPrintf("done!\n");
#endif
/*i = 0;
for (k=0; k < pi_flow[n]; k++)
{
// get the correct row
while (k >= pi_flow[i+1]) { ++i; }
mexPrintf("(%i,%i) (%i,%i)\n", i,j_flow[k],cap[k],res[k]);
}*/
if (nlhs >= 1)
{
plhs[0] = mxCreateDoubleMatrix(1,1, mxREAL);
pflowval = mxGetPr(plhs[0]);
pflowval[0] = (double)flow;
}
if (nlhs >= 2)
{
int *pimincut;
plhs[1] = mxCreateDoubleMatrix(n,1,mxREAL);
pmincut = mxGetPr(plhs[1]);
pimincut = (int*)pmincut;
build_cut(u, n, pi_flow, j_flow, cap, res, pimincut);
test_cut(flow,pimincut,n,A_row,A_col,A_val);
/* now expand mincut to the full dataset, we need to
* do this operation backwards because pimincut has integer
* entries specified and we are expanding them to double.
*/
expand_int_to_double(pimincut,pmincut,n,0.0);
}
if (nlhs >= 3)
{
plhs[2] = mxCreateDoubleMatrix(nz,1,mxREAL);
plhs[3] = mxCreateDoubleMatrix(nz,1,mxREAL);
plhs[4] = mxCreateDoubleMatrix(nz,1,mxREAL);
pri = mxGetPr(plhs[2]);
prj = mxGetPr(plhs[3]);
prv = mxGetPr(plhs[4]);
/* j will be our index into the new matrix. */
j = 0;
for (i=0;i<n;i++)
{
for (k=pi_flow[i];k<pi_flow[i+1];k++)
{
if (cap[k] != 0)
{
/* since cap[k] != 0, this is a real edge */
pri[j] = i+1;
prj[j] = j_flow[k]+1;
prv[j] = res[k];
j++;
}
}
}
if (j != nz)
{
mexPrintf("error... j != nz...\n");
}
}
#ifdef _DEBUG
mexPrintf("return\n");
#endif
}
