/**
* Input arguments: index (pointer), testset (matrix), n (int), params (struct)
* Output arguments: indices(matrix), dists(matrix)
*/
static void _index_find_nn(int nOutArray, mxArray* OutArray[], int nInArray, const mxArray* InArray[])
{
/* Check the number of input arguments */
if(nInArray != 4) {
mexErrMsgTxt("Incorrect number of input arguments");
}
/* Check if there is one Output matrix */
if(nOutArray > 2) {
mexErrMsgTxt("One or two outputs required.");
}
const mxArray* indexMat = InArray[0];
TypedIndex* typedIndex = *(TypedIndex**)mxGetData(indexMat);
const mxArray* testsetMat = InArray[1];
check_allowed_type(testsetMat);
int tcount = mxGetN(testsetMat);
const mxArray* nnMat = InArray[2];
if ((mxGetM(nnMat)!=1)||(mxGetN(nnMat)!=1)) {
mexErrMsgTxt("Number of nearest neighbors should be a scalar.");
}
int nn = (int)(*mxGetPr(nnMat));
int* result = (int*)malloc(tcount*nn*sizeof(int));
float* dists = NULL;
double* ddists = NULL;
const mxArray* pStruct = InArray[3];
FLANNParameters p;
matlabStructToFlannStruct(pStruct, p);
if (mxIsSingle(testsetMat)) {
if (typedIndex->type != FLANN_FLOAT32) {
mexErrMsgTxt("Index type must match testset type");
}
float* testset = (float*) mxGetData(testsetMat);
dists = (float*)malloc(tcount*nn*sizeof(float));
flann_find_nearest_neighbors_index_float(typedIndex->index,testset, tcount, result, dists, nn, &p);
}
else if (mxIsDouble(testsetMat)) {
if (typedIndex->type != FLANN_FLOAT64) {
mexErrMsgTxt("Index type must match testset type");
}
double* testset = (double*) mxGetData(testsetMat);
ddists = (double*)malloc(tcount*nn*sizeof(double));
flann_find_nearest_neighbors_index_double(typedIndex->index,testset, tcount, result, ddists, nn, &p);
}
else if (mxIsUint8(testsetMat)) {
if (typedIndex->type != FLANN_UINT8) {
mexErrMsgTxt("Index type must match testset type");
}
unsigned char* testset = (unsigned char*) mxGetData(testsetMat);
dists = (float*)malloc(tcount*nn*sizeof(float));
flann_find_nearest_neighbors_index_byte(typedIndex->index,testset, tcount, result, dists, nn, &p);
}
else if (mxIsInt32(testsetMat)) {
if (typedIndex->type != FLANN_INT32) {
mexErrMsgTxt("Index type must match testset type");
}
int* testset = (int*) mxGetData(testsetMat);
dists = (float*)malloc(tcount*nn*sizeof(float));
flann_find_nearest_neighbors_index_int(typedIndex->index,testset, tcount, result, dists, nn, &p);
}
/* Allocate memory for Output Matrix */
OutArray[0] = mxCreateDoubleMatrix(nn, tcount, mxREAL);
/* Get pointer to Output matrix and store result*/
double* pOut = mxGetPr(OutArray[0]);
for (int i=0; i<tcount*nn; ++i) {
pOut[i] = result[i]+1; // matlab uses 1-based indexing
}
free(result);
if (nOutArray > 1) {
/* Allocate memory for Output Matrix */
OutArray[1] = mxCreateDoubleMatrix(nn, tcount, mxREAL);
/* Get pointer to Output matrix and store result*/
double* pDists = mxGetPr(OutArray[1]);
if (dists!=NULL) {
for (int i=0; i<tcount*nn; ++i) {
pDists[i] = dists[i];
}
}
if (ddists!=NULL) {
for (int i=0; i<tcount*nn; ++i) {
pDists[i] = ddists[i];
}
}
}
if (dists!=NULL) free(dists);
if (ddists!=NULL) free(ddists);
}
int NearestNode(MacroMesh *m, real *xphy) {
int nearest = -1;
#ifdef _WITH_FLANN
// Use of flann library: faster ???
static bool is_ready = false;
static struct FLANNParameters p;
static float speedup;
static flann_index_t findex;
// at first call: construct the index
// TO DO free the index when finished
if (!is_ready) {
printf("Using flann: build search index...\n");
p = DEFAULT_FLANN_PARAMETERS;
p.algorithm = FLANN_INDEX_AUTOTUNED;
p.target_precision = 0.9; /* want 90% target precision */
#if real == double
findex = flann_build_index_double(m->node, m->nbnodes, 3, &speedup, &p);
#else
findex = flann_build_index_float(m->node, m->nbnodes, 3, &speedup, &p);
#endif
is_ready = true;
}
// number of nearest neighbors to search
int nn = 1;
int result[nn];
real dists[nn];
// compute the nn nearest-neighbors of each point in xphy
// with index construction
// flann_find_nearest_neighbors_real(m->node, // nodes list
// m->nbnodes, // number of nodes
// 3, // space dim
// xphy,
// 1, // number of points in xphy
// result, // nearest points indices
// dists, // distances
// nn,
// &p); // flan struct
#if real == double
flann_find_nearest_neighbors_index_double(findex,// index
xphy,
1, // number of points in xphy
result, // nearest points indices
dists, // distances
nn,
&p); // flan struct
#else
flann_find_nearest_neighbors_index_float(findex,// index
xphy,
1, // number of points in xphy
result, // nearest points indices
dists, // distances
nn,
&p); // flan struct
#endif
nearest = result[0];
// printf("xphy=%f %f %f nearest=%d %f %f %f \n",
// xphy[0],xphy[1],xphy[2],nearest+1,
// m->node[0+nearest*3],m->node[1+nearest*3],m->node[2+nearest*3]);
#else // Do not use FLANN library.
// slow version: loops on all the points
real d = 1e20;
for(int ino = 0; ino < m->nbnodes; ino++){
real d2 = Dist(xphy, m->node + 3 * ino);
if (d2 < d) {
nearest = ino;
d = d2;
}
}
#endif
return nearest;
}
