int main( int argc, char *argv[])
{
/* field variables */
LSMLIB_REAL *phi;
LSMLIB_REAL *distance_function;
LSMLIB_REAL *mask = 0;
/* grid parameters */
LSMLIB_REAL X_lo[2] = {-1.0,-1.0};
LSMLIB_REAL X_hi[2] = {1.0,1.0};
LSMLIB_REAL dx[2];
int N;
int i,j;
int idx;
int num_gridpts;
int grid_dims[2];
/* numerical parameters */
int spatial_derivative_order = 2;
/* auxilliary variables */
LSMLIB_REAL x,y;
LSMLIB_REAL center[2], radius;
/* file pointer to output results */
FILE *data_file;
/* set up grid */
N = 100;
num_gridpts = 1;
for (i = 0; i < 2; i++) {
dx[i] = (X_hi[i]-X_lo[i])/N;
grid_dims[i] = N+1;
num_gridpts *= grid_dims[i];
}
/* allocate memory for field data */
phi = (LSMLIB_REAL*) malloc(num_gridpts*sizeof(LSMLIB_REAL));
distance_function = (LSMLIB_REAL*) malloc(num_gridpts*sizeof(LSMLIB_REAL));
/* initialize data */
center[0] = 0.0; center[1] = 0.0;
radius = 0.5;
for (j = 0; j < grid_dims[1]; j++) {
for (i = 0; i < grid_dims[0]; i++) {
idx = i+j*grid_dims[0];
x = X_lo[0]+dx[0]*i;
y = X_lo[1]+dx[1]*j;
phi[idx] = ( (x-center[0])*(x-center[0])
+(y-center[1])*(y-center[1]) ) - radius*radius;
}
}
for (i = 0; i < num_gridpts; i++) {
distance_function[i] = 0;
}
/* Carry out FMM calculation */
computeDistanceFunction2d(
distance_function,
phi,
mask,
spatial_derivative_order,
grid_dims,
dx);
/* write results to output file */
data_file = fopen("computeDistanceFunction2d.dat","w");
for (idx = 0; idx < num_gridpts; idx++) {
fprintf(data_file,"%f %f\n", distance_function[idx],phi[idx]);
}
fclose(data_file);
/* clean up memory */
free(phi);
free(distance_function);
return(0);
}
void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
/* field data */
double *phi;
double *mask;
double **ext_fields_orig;
double *distance_fcn;
double **ext_fields_updated;
int num_ext_fields;
/* grid data */
const int *grid_dims = mxGetDimensions(PHI);
double *dX = mxGetPr(DX);
double dX_matlab_order[2];
/* numerical parameters */
int spatial_derivative_order;
/* auxilliary variables */
int i;
int error_code;
mxArray* tmp_mxArray;
/* Check for proper number of arguments */
if (nrhs < 2) {
mexErrMsgTxt(
"Insufficient number of input arguments (2 required; 2 optional)");
} else if (nrhs > 4) {
mexErrMsgTxt("Too many input arguments (2 required; 2 optional)");
} else if (nlhs > 1) {
mexErrMsgTxt("Too many output arguments.");
}
/* Get mask */
if (nrhs < 3) {
mask = 0; /* NULL mask ==> all points are in interior of domain */
} else {
mask = mxGetPr(MASK);
}
/* Get spatial derivative order */
if (nrhs < 4) {
spatial_derivative_order = 1; /* KTC - change this to 2 after */
/* implementing second-order algorithm */
} else {
spatial_derivative_order = (int)(mxGetPr(SPATIAL_DERIVATIVE_ORDER)[0]);
}
/* Assign pointers for phi data */
phi = mxGetPr(PHI);
/* Create distance function data */
DISTANCE_FUNCTION = mxCreateDoubleMatrix(grid_dims[0], grid_dims[1], mxREAL);
distance_fcn = mxGetPr(DISTANCE_FUNCTION);
/* Change order of dX to be match MATLAB meshgrid() order for grids. */
dX_matlab_order[0] = dX[1];
dX_matlab_order[1] = dX[0];
/* Carry out FMM calculation */
error_code = computeDistanceFunction2d(
distance_fcn,
phi,
mask,
spatial_derivative_order,
(int*) grid_dims,
dX_matlab_order);
if (error_code) {
mexErrMsgTxt("computeDistanceFunction2d failed...");
}
return;
}
