gk_graph_t *gk_graph_ExtractPartition(gk_graph_t *graph, int *part, int pid)
{
ssize_t i, j, nnz;
gk_graph_t *ngraph;
ngraph = gk_graph_Create();
ngraph->nrows = 0;
ngraph->ncols = graph->ncols;
for (nnz=0, i=0; i<graph->nrows; i++) {
if (part[i] == pid) {
ngraph->nrows++;
nnz += graph->rowptr[i+1]-graph->rowptr[i];
}
}
ngraph->rowptr = gk_zmalloc(ngraph->nrows+1, "gk_graph_ExtractPartition: rowptr");
ngraph->rowind = gk_imalloc(nnz, "gk_graph_ExtractPartition: rowind");
ngraph->rowval = gk_fmalloc(nnz, "gk_graph_ExtractPartition: rowval");
ngraph->rowptr[0] = 0;
for (nnz=0, j=0, i=0; i<graph->nrows; i++) {
if (part[i] == pid) {
gk_icopy(graph->rowptr[i+1]-graph->rowptr[i], graph->rowind+graph->rowptr[i], ngraph->rowind+nnz);
gk_fcopy(graph->rowptr[i+1]-graph->rowptr[i], graph->rowval+graph->rowptr[i], ngraph->rowval+nnz);
nnz += graph->rowptr[i+1]-graph->rowptr[i];
ngraph->rowptr[++j] = nnz;
}
}
ASSERT(j == ngraph->nrows);
return ngraph;
}
gk_graph_t *gk_graph_ExtractRows(gk_graph_t *graph, int nrows, int *rind)
{
ssize_t i, ii, j, nnz;
gk_graph_t *ngraph;
ngraph = gk_graph_Create();
ngraph->nrows = nrows;
ngraph->ncols = graph->ncols;
for (nnz=0, i=0; i<nrows; i++)
nnz += graph->rowptr[rind[i]+1]-graph->rowptr[rind[i]];
ngraph->rowptr = gk_zmalloc(ngraph->nrows+1, "gk_graph_ExtractPartition: rowptr");
ngraph->rowind = gk_imalloc(nnz, "gk_graph_ExtractPartition: rowind");
ngraph->rowval = gk_fmalloc(nnz, "gk_graph_ExtractPartition: rowval");
ngraph->rowptr[0] = 0;
for (nnz=0, j=0, ii=0; ii<nrows; ii++) {
i = rind[ii];
gk_icopy(graph->rowptr[i+1]-graph->rowptr[i], graph->rowind+graph->rowptr[i], ngraph->rowind+nnz);
gk_fcopy(graph->rowptr[i+1]-graph->rowptr[i], graph->rowval+graph->rowptr[i], ngraph->rowval+nnz);
nnz += graph->rowptr[i+1]-graph->rowptr[i];
ngraph->rowptr[++j] = nnz;
}
ASSERT(j == ngraph->nrows);
return ngraph;
}
gk_graph_t *gk_graph_ExtractSubgraph(gk_graph_t *graph, int vstart, int nvtxs)
{
ssize_t i;
gk_graph_t *ngraph;
if (vstart+nvtxs > graph->nvtxs)
return NULL;
ngraph = gk_graph_Create();
ngraph->nvtxs = nvtxs;
/* copy the adjancy structure */
if (graph->xadj)
ngraph->xadj = gk_zcopy(nvtxs+1, graph->xadj+vstart,
gk_zmalloc(nvtxs+1, "gk_graph_ExtractSubgraph: xadj"));
for (i=nvtxs; i>=0; i--)
ngraph->xadj[i] -= ngraph->xadj[0];
ASSERT(ngraph->xadj[0] == 0);
if (graph->ivwgts)
ngraph->ivwgts = gk_i32copy(nvtxs, graph->ivwgts+vstart,
gk_i32malloc(nvtxs, "gk_graph_ExtractSubgraph: ivwgts"));
if (graph->ivsizes)
ngraph->ivsizes = gk_i32copy(nvtxs, graph->ivsizes+vstart,
gk_i32malloc(nvtxs, "gk_graph_ExtractSubgraph: ivsizes"));
if (graph->vlabels)
ngraph->vlabels = gk_i32copy(nvtxs, graph->vlabels+vstart,
gk_i32malloc(nvtxs, "gk_graph_ExtractSubgraph: vlabels"));
if (graph->fvwgts)
ngraph->fvwgts = gk_fcopy(nvtxs, graph->fvwgts+vstart,
gk_fmalloc(nvtxs, "gk_graph_ExtractSubgraph: fvwgts"));
if (graph->fvsizes)
ngraph->fvsizes = gk_fcopy(nvtxs, graph->fvsizes+vstart,
gk_fmalloc(nvtxs, "gk_graph_ExtractSubgraph: fvsizes"));
ASSERT(ngraph->xadj[nvtxs] == graph->xadj[vstart+nvtxs]-graph->xadj[vstart]);
if (graph->adjncy)
ngraph->adjncy = gk_i32copy(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
graph->adjncy+graph->xadj[vstart],
gk_i32malloc(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
"gk_graph_ExtractSubgraph: adjncy"));
if (graph->iadjwgt)
ngraph->iadjwgt = gk_i32copy(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
graph->iadjwgt+graph->xadj[vstart],
gk_i32malloc(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
"gk_graph_ExtractSubgraph: iadjwgt"));
if (graph->fadjwgt)
ngraph->fadjwgt = gk_fcopy(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
graph->fadjwgt+graph->xadj[vstart],
gk_fmalloc(graph->xadj[vstart+nvtxs]-graph->xadj[vstart],
"gk_graph_ExtractSubgraph: fadjwgt"));
return ngraph;
}
void gk_find_frequent_itemsets(int ntrans, int *tranptr, int *tranind,
int minfreq, int maxfreq, int minlen, int maxlen,
void (*process_itemset)(void *stateptr, int nitems, int *itemids,
int ntrans, int *transids),
void *stateptr)
{
ssize_t i;
gk_csr_t *mat, *pmat;
isparams_t params;
int *pattern;
/* Create the matrix */
mat = gk_csr_Create();
mat->nrows = ntrans;
mat->ncols = tranind[gk_iargmax(tranptr[ntrans], tranind)]+1;
mat->rowptr = gk_zmalloc(ntrans+1, "gk_find_frequent_itemsets: mat.rowptr");
for (i=0; i<ntrans+1; i++)
mat->rowptr[i] = tranptr[i];
mat->rowind = gk_icopy(tranptr[ntrans], tranind, gk_imalloc(tranptr[ntrans], "gk_find_frequent_itemsets: mat.rowind"));
mat->colids = gk_iincset(mat->ncols, 0, gk_imalloc(mat->ncols, "gk_find_frequent_itemsets: mat.colids"));
/* Setup the parameters */
params.minfreq = minfreq;
params.maxfreq = (maxfreq == -1 ? mat->nrows : maxfreq);
params.minlen = minlen;
params.maxlen = (maxlen == -1 ? mat->ncols : maxlen);
params.tnitems = mat->ncols;
params.callback = process_itemset;
params.stateptr = stateptr;
params.rmarker = gk_ismalloc(mat->nrows, 0, "gk_find_frequent_itemsets: rmarker");
params.cand = gk_ikvmalloc(mat->ncols, "gk_find_frequent_itemsets: cand");
/* Perform the initial projection */
gk_csr_CreateIndex(mat, GK_CSR_COL);
pmat = itemsets_project_matrix(¶ms, mat, -1);
gk_csr_Free(&mat);
pattern = gk_imalloc(pmat->ncols, "gk_find_frequent_itemsets: pattern");
itemsets_find_frequent_itemsets(¶ms, pmat, 0, pattern);
gk_csr_Free(&pmat);
gk_free((void **)&pattern, ¶ms.rmarker, ¶ms.cand, LTERM);
}
gk_graph_t *gk_graph_Dup(gk_graph_t *graph)
{
gk_graph_t *ngraph;
ngraph = gk_graph_Create();
ngraph->nvtxs = graph->nvtxs;
/* copy the adjacency structure */
if (graph->xadj)
ngraph->xadj = gk_zcopy(graph->nvtxs+1, graph->xadj,
gk_zmalloc(graph->nvtxs+1, "gk_graph_Dup: xadj"));
if (graph->ivwgts)
ngraph->ivwgts = gk_i32copy(graph->nvtxs, graph->ivwgts,
gk_i32malloc(graph->nvtxs, "gk_graph_Dup: ivwgts"));
if (graph->ivsizes)
ngraph->ivsizes = gk_i32copy(graph->nvtxs, graph->ivsizes,
gk_i32malloc(graph->nvtxs, "gk_graph_Dup: ivsizes"));
if (graph->vlabels)
ngraph->vlabels = gk_i32copy(graph->nvtxs, graph->vlabels,
gk_i32malloc(graph->nvtxs, "gk_graph_Dup: ivlabels"));
if (graph->fvwgts)
ngraph->fvwgts = gk_fcopy(graph->nvtxs, graph->fvwgts,
gk_fmalloc(graph->nvtxs, "gk_graph_Dup: fvwgts"));
if (graph->fvsizes)
ngraph->fvsizes = gk_fcopy(graph->nvtxs, graph->fvsizes,
gk_fmalloc(graph->nvtxs, "gk_graph_Dup: fvsizes"));
if (graph->adjncy)
ngraph->adjncy = gk_i32copy(graph->xadj[graph->nvtxs], graph->adjncy,
gk_i32malloc(graph->xadj[graph->nvtxs], "gk_graph_Dup: adjncy"));
if (graph->iadjwgt)
ngraph->iadjwgt = gk_i32copy(graph->xadj[graph->nvtxs], graph->iadjwgt,
gk_i32malloc(graph->xadj[graph->nvtxs], "gk_graph_Dup: iadjwgt"));
if (graph->fadjwgt)
ngraph->fadjwgt = gk_fcopy(graph->xadj[graph->nvtxs], graph->fadjwgt,
gk_fmalloc(graph->xadj[graph->nvtxs], "gk_graph_Dup: fadjwgt"));
return ngraph;
}
gk_csr_t *itemsets_project_matrix(isparams_t *params, gk_csr_t *mat, int cid)
{
ssize_t i, j, k, ii, pnnz;
int nrows, ncols, pnrows, pncols;
ssize_t *colptr, *pcolptr;
int *colind, *colids, *pcolind, *pcolids, *rmarker;
gk_csr_t *pmat;
gk_ikv_t *cand;
nrows = mat->nrows;
ncols = mat->ncols;
colptr = mat->colptr;
colind = mat->colind;
colids = mat->colids;
rmarker = params->rmarker;
cand = params->cand;
/* Allocate space for the projected matrix based on what you know thus far */
pmat = gk_csr_Create();
pmat->nrows = pnrows = (cid == -1 ? nrows : colptr[cid+1]-colptr[cid]);
/* Mark the rows that will be kept and determine the prowids */
if (cid == -1) { /* Initial projection */
gk_iset(nrows, 1, rmarker);
}
else { /* The other projections */
for (i=colptr[cid]; i<colptr[cid+1]; i++)
rmarker[colind[i]] = 1;
}
/* Determine the length of each column that will be left in the projected matrix */
for (pncols=0, pnnz=0, i=cid+1; i<ncols; i++) {
for (k=0, j=colptr[i]; j<colptr[i+1]; j++) {
k += rmarker[colind[j]];
}
if (k >= params->minfreq && k <= params->maxfreq) {
cand[pncols].val = i;
cand[pncols++].key = k;
pnnz += k;
}
}
/* Sort the columns in increasing order */
gk_ikvsorti(pncols, cand);
/* Allocate space for the remaining fields of the projected matrix */
pmat->ncols = pncols;
pmat->colids = pcolids = gk_imalloc(pncols, "itemsets_project_matrix: pcolids");
pmat->colptr = pcolptr = gk_zmalloc(pncols+1, "itemsets_project_matrix: pcolptr");
pmat->colind = pcolind = gk_imalloc(pnnz, "itemsets_project_matrix: pcolind");
/* Populate the projected matrix */
pcolptr[0] = 0;
for (pnnz=0, ii=0; ii<pncols; ii++) {
i = cand[ii].val;
for (j=colptr[i]; j<colptr[i+1]; j++) {
if (rmarker[colind[j]])
pcolind[pnnz++] = colind[j];
}
pcolids[ii] = colids[i];
pcolptr[ii+1] = pnnz;
}
/* Reset the rmarker array */
if (cid == -1) { /* Initial projection */
gk_iset(nrows, 0, rmarker);
}
else { /* The other projections */
for (i=colptr[cid]; i<colptr[cid+1]; i++)
rmarker[colind[i]] = 0;
}
return pmat;
}
gk_graph_t *gk_graph_Read(char *filename, int format, int isfewgts,
int isfvwgts, int isfvsizes)
{
ssize_t i, k, l;
size_t nfields, nvtxs, nedges, fmt, ncon, lnlen;
int32_t ival;
float fval;
int readsizes=0, readwgts=0, readvals=0, numbering=0;
char *line=NULL, *head, *tail, fmtstr[256];
FILE *fpin=NULL;
gk_graph_t *graph=NULL;
if (!gk_fexists(filename))
gk_errexit(SIGERR, "File %s does not exist!\n", filename);
if (format == GK_GRAPH_FMT_METIS) {
fpin = gk_fopen(filename, "r", "gk_graph_Read: fpin");
do {
if (gk_getline(&line, &lnlen, fpin) <= 0)
gk_errexit(SIGERR, "Premature end of input file: file:%s\n", filename);
} while (line[0] == '%');
fmt = ncon = 0;
nfields = sscanf(line, "%zu %zu %zu %zu", &nvtxs, &nedges, &fmt, &ncon);
if (nfields < 2)
gk_errexit(SIGERR, "Header line must contain at least 2 integers (#vtxs and #edges).\n");
nedges *= 2;
if (fmt > 111)
gk_errexit(SIGERR, "Cannot read this type of file format [fmt=%zu]!\n", fmt);
sprintf(fmtstr, "%03zu", fmt%1000);
readsizes = (fmtstr[0] == '1');
readwgts = (fmtstr[1] == '1');
readvals = (fmtstr[2] == '1');
numbering = 1;
ncon = (ncon == 0 ? 1 : ncon);
}
else {
gk_errexit(SIGERR, "Unrecognized format: %d\n", format);
}
graph = gk_graph_Create();
graph->nvtxs = nvtxs;
graph->xadj = gk_zmalloc(nvtxs+1, "gk_graph_Read: xadj");
graph->adjncy = gk_i32malloc(nedges, "gk_graph_Read: adjncy");
if (readvals) {
if (isfewgts)
graph->fadjwgt = gk_fmalloc(nedges, "gk_graph_Read: fadjwgt");
else
graph->iadjwgt = gk_i32malloc(nedges, "gk_graph_Read: iadjwgt");
}
if (readsizes) {
if (isfvsizes)
graph->fvsizes = gk_fmalloc(nvtxs, "gk_graph_Read: fvsizes");
else
graph->ivsizes = gk_i32malloc(nvtxs, "gk_graph_Read: ivsizes");
}
if (readwgts) {
if (isfvwgts)
graph->fvwgts = gk_fmalloc(nvtxs*ncon, "gk_graph_Read: fvwgts");
else
graph->ivwgts = gk_i32malloc(nvtxs*ncon, "gk_graph_Read: ivwgts");
}
/*----------------------------------------------------------------------
* Read the sparse graph file
*---------------------------------------------------------------------*/
numbering = (numbering ? - 1 : 0);
for (graph->xadj[0]=0, k=0, i=0; i<nvtxs; i++) {
do {
if (gk_getline(&line, &lnlen, fpin) == -1)
gk_errexit(SIGERR, "Pregraphure end of input file: file while reading row %d\n", i);
} while (line[0] == '%');
head = line;
tail = NULL;
/* Read vertex sizes */
if (readsizes) {
if (isfvsizes) {
#ifdef __MSC__
graph->fvsizes[i] = (float)strtod(head, &tail);
#else
graph->fvsizes[i] = strtof(head, &tail);
#endif
if (tail == head)
gk_errexit(SIGERR, "The line for vertex %zd does not have size information\n", i+1);
if (graph->fvsizes[i] < 0)
gk_errexit(SIGERR, "The size for vertex %zd must be >= 0\n", i+1);
}
else {
graph->ivsizes[i] = strtol(head, &tail, 0);
if (tail == head)
gk_errexit(SIGERR, "The line for vertex %zd does not have size information\n", i+1);
if (graph->ivsizes[i] < 0)
gk_errexit(SIGERR, "The size for vertex %zd must be >= 0\n", i+1);
}
head = tail;
}
/* Read vertex weights */
if (readwgts) {
for (l=0; l<ncon; l++) {
if (isfvwgts) {
#ifdef __MSC__
graph->fvwgts[i*ncon+l] = (float)strtod(head, &tail);
#else
graph->fvwgts[i*ncon+l] = strtof(head, &tail);
#endif
if (tail == head)
gk_errexit(SIGERR, "The line for vertex %zd does not have enough weights "
"for the %d constraints.\n", i+1, ncon);
if (graph->fvwgts[i*ncon+l] < 0)
gk_errexit(SIGERR, "The weight vertex %zd and constraint %zd must be >= 0\n", i+1, l);
}
else {
graph->ivwgts[i*ncon+l] = strtol(head, &tail, 0);
if (tail == head)
gk_errexit(SIGERR, "The line for vertex %zd does not have enough weights "
"for the %d constraints.\n", i+1, ncon);
if (graph->ivwgts[i*ncon+l] < 0)
gk_errexit(SIGERR, "The weight vertex %zd and constraint %zd must be >= 0\n", i+1, l);
}
head = tail;
}
}
/* Read the rest of the row */
while (1) {
ival = (int)strtol(head, &tail, 0);
if (tail == head)
break;
head = tail;
if ((graph->adjncy[k] = ival + numbering) < 0)
gk_errexit(SIGERR, "Error: Invalid column number %d at row %zd.\n", ival, i);
if (readvals) {
if (isfewgts) {
#ifdef __MSC__
fval = (float)strtod(head, &tail);
#else
fval = strtof(head, &tail);
#endif
if (tail == head)
gk_errexit(SIGERR, "Value could not be found for edge! Vertex:%zd, NNZ:%zd\n", i, k);
graph->fadjwgt[k] = fval;
}
else {
ival = strtol(head, &tail, 0);
if (tail == head)
gk_errexit(SIGERR, "Value could not be found for edge! Vertex:%zd, NNZ:%zd\n", i, k);
graph->iadjwgt[k] = ival;
}
head = tail;
}
k++;
}
graph->xadj[i+1] = k;
}
if (k != nedges)
gk_errexit(SIGERR, "gk_graph_Read: Something wrong with the number of edges in "
"the input file. nedges=%zd, Actualnedges=%zd.\n", nedges, k);
gk_fclose(fpin);
gk_free((void **)&line, LTERM);
return graph;
}
gk_graph_t *gk_graph_Reorder(gk_graph_t *graph, int32_t *perm, int32_t *iperm)
{
ssize_t j, jj, *xadj;
int i, k, u, v, nvtxs;
int freeperm=0, freeiperm=0;
int32_t *adjncy;
gk_graph_t *ngraph;
if (perm == NULL && iperm == NULL)
return NULL;
ngraph = gk_graph_Create();
ngraph->nvtxs = nvtxs = graph->nvtxs;
xadj = graph->xadj;
adjncy = graph->adjncy;
/* allocate memory for the different structures that are present in graph */
if (graph->xadj)
ngraph->xadj = gk_zmalloc(nvtxs+1, "gk_graph_Reorder: xadj");
if (graph->ivwgts)
ngraph->ivwgts = gk_i32malloc(nvtxs, "gk_graph_Reorder: ivwgts");
if (graph->ivsizes)
ngraph->ivsizes = gk_i32malloc(nvtxs, "gk_graph_Reorder: ivsizes");
if (graph->vlabels)
ngraph->vlabels = gk_i32malloc(nvtxs, "gk_graph_Reorder: ivlabels");
if (graph->fvwgts)
ngraph->fvwgts = gk_fmalloc(nvtxs, "gk_graph_Reorder: fvwgts");
if (graph->fvsizes)
ngraph->fvsizes = gk_fmalloc(nvtxs, "gk_graph_Reorder: fvsizes");
if (graph->adjncy)
ngraph->adjncy = gk_i32malloc(graph->xadj[nvtxs], "gk_graph_Reorder: adjncy");
if (graph->iadjwgt)
ngraph->iadjwgt = gk_i32malloc(graph->xadj[nvtxs], "gk_graph_Reorder: iadjwgt");
if (graph->fadjwgt)
ngraph->fadjwgt = gk_fmalloc(graph->xadj[nvtxs], "gk_graph_Reorder: fadjwgt");
/* create perm/iperm if not provided */
if (perm == NULL) {
freeperm = 1;
perm = gk_i32malloc(nvtxs, "gk_graph_Reorder: perm");
for (i=0; i<nvtxs; i++)
perm[iperm[i]] = i;
}
if (iperm == NULL) {
freeiperm = 1;
iperm = gk_i32malloc(nvtxs, "gk_graph_Reorder: iperm");
for (i=0; i<nvtxs; i++)
iperm[perm[i]] = i;
}
/* fill-in the information of the re-ordered graph */
ngraph->xadj[0] = jj = 0;
for (v=0; v<nvtxs; v++) {
u = iperm[v];
for (j=xadj[u]; j<xadj[u+1]; j++, jj++) {
ngraph->adjncy[jj] = perm[adjncy[j]];
if (graph->iadjwgt)
ngraph->iadjwgt[jj] = graph->iadjwgt[j];
if (graph->fadjwgt)
ngraph->fadjwgt[jj] = graph->fadjwgt[j];
}
if (graph->ivwgts)
ngraph->ivwgts[v] = graph->ivwgts[u];
if (graph->fvwgts)
ngraph->fvwgts[v] = graph->fvwgts[u];
if (graph->ivsizes)
ngraph->ivsizes[v] = graph->ivsizes[u];
if (graph->fvsizes)
ngraph->fvsizes[v] = graph->fvsizes[u];
if (graph->vlabels)
ngraph->vlabels[v] = graph->vlabels[u];
ngraph->xadj[v+1] = jj;
}
/* free memory */
if (freeperm)
gk_free((void **)&perm, LTERM);
if (freeiperm)
gk_free((void **)&iperm, LTERM);
return ngraph;
}
gk_graph_t *gk_graph_Prune(gk_graph_t *graph, int what, int minf, int maxf)
{
ssize_t i, j, nnz;
int nrows, ncols;
ssize_t *rowptr, *nrowptr;
int *rowind, *nrowind, *collen;
float *rowval, *nrowval;
gk_graph_t *ngraph;
ngraph = gk_graph_Create();
nrows = ngraph->nrows = graph->nrows;
ncols = ngraph->ncols = graph->ncols;
rowptr = graph->rowptr;
rowind = graph->rowind;
rowval = graph->rowval;
nrowptr = ngraph->rowptr = gk_zmalloc(nrows+1, "gk_graph_Prune: nrowptr");
nrowind = ngraph->rowind = gk_imalloc(rowptr[nrows], "gk_graph_Prune: nrowind");
nrowval = ngraph->rowval = gk_fmalloc(rowptr[nrows], "gk_graph_Prune: nrowval");
switch (what) {
case GK_CSR_COL:
collen = gk_ismalloc(ncols, 0, "gk_graph_Prune: collen");
for (i=0; i<nrows; i++) {
for (j=rowptr[i]; j<rowptr[i+1]; j++) {
ASSERT(rowind[j] < ncols);
collen[rowind[j]]++;
}
}
for (i=0; i<ncols; i++)
collen[i] = (collen[i] >= minf && collen[i] <= maxf ? 1 : 0);
nrowptr[0] = 0;
for (nnz=0, i=0; i<nrows; i++) {
for (j=rowptr[i]; j<rowptr[i+1]; j++) {
if (collen[rowind[j]]) {
nrowind[nnz] = rowind[j];
nrowval[nnz] = rowval[j];
nnz++;
}
}
nrowptr[i+1] = nnz;
}
gk_free((void **)&collen, LTERM);
break;
case GK_CSR_ROW:
nrowptr[0] = 0;
for (nnz=0, i=0; i<nrows; i++) {
if (rowptr[i+1]-rowptr[i] >= minf && rowptr[i+1]-rowptr[i] <= maxf) {
for (j=rowptr[i]; j<rowptr[i+1]; j++, nnz++) {
nrowind[nnz] = rowind[j];
nrowval[nnz] = rowval[j];
}
}
nrowptr[i+1] = nnz;
}
break;
default:
gk_graph_Free(&ngraph);
gk_errexit(SIGERR, "Unknown prunning type of %d\n", what);
return NULL;
}
return ngraph;
}
