/**
* Tests that a given interpolation type reproduces the data points it is given,
* and then tests that it correctly reproduces additional values.
*
* @param xarr the x values of the points that define the function
* @param yarr the y values of the points that define the function
* @param zarr the values of the function at the points specified by xarr and yarr
* @param xsize the length of xarr
* @param ysize the length of yarr
* @param xval the x values of additional points at which to calculate interpolated values
* @param yval the y values of additional points at which to calculate interpolated values
* @param zval the expected results of the additional interpolations
* @param zxval the expected results of the x derivative calculations
* @param zyval the expected results of the y derivative calculations
* @param zxxval the expected results of the xx derivative calculations
* @param zyyval the expected results of the yy derivative calculations
* @param zxyval the expected results of the xy derivative calculations
* @param test_size the length of xval, yval, zval, etc.
* @param T the interpolation type
*/
int test_interp2d(const double xarr[], const double yarr[], const double zarr[], // interpolation data
size_t xsize, size_t ysize, // sizes of xarr and yarr
const double xval[], const double yval[], // test points
const double zval[], // expected results
const double zxval[], const double zyval[],
const double zxxval[], const double zyyval[], const double zxyval[],
size_t test_size, // number of test points
const interp2d_type* T) {
gsl_interp_accel *xa, *ya;
int status = 0;
size_t xi, yi, zi, i;
xa = gsl_interp_accel_alloc();
ya = gsl_interp_accel_alloc();
interp2d* interp = interp2d_alloc(T, xsize, ysize);
interp2d_spline* interp_s = interp2d_spline_alloc(T, xsize, ysize);
unsigned int min_size = interp2d_type_min_size(T);
gsl_test_int(min_size, T->min_size, "interp2d_type_min_size on %s", interp2d_name(interp));
interp2d_init(interp, xarr, yarr, zarr, xsize, ysize);
interp2d_spline_init(interp_s, xarr, yarr, zarr, xsize, ysize);
// First check that the interpolation reproduces the given points
for (xi = 0; xi < xsize; xi++) {
double x = xarr[xi];
for (yi = 0; yi < ysize; yi++) {
double y = yarr[yi];
zi = INDEX_2D(xi, yi, xsize, ysize);
test_single_low_level(&interp2d_eval, &interp2d_eval_e, interp, xarr, yarr, zarr, x, y, xa, ya, zarr, zi);
test_single_low_level(&interp2d_eval_no_boundary_check, &interp2d_eval_e_no_boundary_check, interp, xarr, yarr, zarr, x, y, xa, ya, zarr, zi);
test_single_high_level(&interp2d_spline_eval, &interp2d_spline_eval_e, interp_s, x, y, xa, ya, zarr, zi);
}
}
// Then check additional points provided
for (i = 0; i < test_size; i++) {
double x = xval[i];
double y = yval[i];
test_single_low_level(&interp2d_eval, &interp2d_eval_e, interp, xarr, yarr, zarr, x, y, xa, ya, zval, i);
test_single_low_level(&interp2d_eval_deriv_x, &interp2d_eval_deriv_x_e, interp, xarr, yarr, zarr, x, y, xa, ya, zxval, i);
test_single_low_level(&interp2d_eval_deriv_y, &interp2d_eval_deriv_y_e, interp, xarr, yarr, zarr, x, y, xa, ya, zyval, i);
test_single_low_level(&interp2d_eval_deriv_xx,&interp2d_eval_deriv_xx_e, interp, xarr, yarr, zarr, x, y, xa, ya, zxxval, i);
test_single_low_level(&interp2d_eval_deriv_yy,&interp2d_eval_deriv_yy_e, interp, xarr, yarr, zarr, x, y, xa, ya, zyyval, i);
test_single_low_level(&interp2d_eval_deriv_xy,&interp2d_eval_deriv_xy_e, interp, xarr, yarr, zarr, x, y, xa, ya, zxyval, i);
test_single_high_level(&interp2d_spline_eval, &interp2d_spline_eval_e, interp_s, x, y, xa, ya, zval, i);
test_single_high_level(&interp2d_spline_eval_deriv_x, &interp2d_spline_eval_deriv_x_e, interp_s, x, y, xa, ya, zxval, i);
test_single_high_level(&interp2d_spline_eval_deriv_y, &interp2d_spline_eval_deriv_y_e, interp_s, x, y, xa, ya, zyval, i);
test_single_high_level(&interp2d_spline_eval_deriv_xx,&interp2d_spline_eval_deriv_xx_e, interp_s, x, y, xa, ya, zxxval, i);
test_single_high_level(&interp2d_spline_eval_deriv_yy,&interp2d_spline_eval_deriv_yy_e, interp_s, x, y, xa, ya, zyyval, i);
test_single_high_level(&interp2d_spline_eval_deriv_xy,&interp2d_spline_eval_deriv_xy_e, interp_s, x, y, xa, ya, zxyval, i);
test_single_low_level(&interp2d_eval_no_boundary_check, &interp2d_eval_e_no_boundary_check, interp, xarr, yarr, zarr, x, y, xa, ya, zval, i);
}
gsl_interp_accel_free(xa);
gsl_interp_accel_free(ya);
interp2d_free(interp);
return status;
}
void velinterp (struct drifter *ptdrifter, int ndr, int xdim, int ydim, const double *u, const double *v){
int i, j;
double *xarr, *yarr;
xarr = new double[xdim];
yarr = new double[ydim];
for (i = 0; i < xdim; i++)
xarr[i] = i * 1.0;
for (j = 0; j < ydim; j++)
yarr[j] = j * 1.0;
gsl_interp_accel *xa, *ya;
const interp2d_type* T = interp2d_bicubic;
xa = gsl_interp_accel_alloc();
ya = gsl_interp_accel_alloc();
interp2d_spline* interp_u = interp2d_spline_alloc(T, xdim, ydim);
interp2d_spline* interp_v = interp2d_spline_alloc(T, xdim, ydim);
interp2d_spline_init(interp_u, xarr, yarr, u, xdim, ydim);
interp2d_spline_init(interp_v, xarr, yarr, v, xdim, ydim);
double xdr, ydr;
for (i = 0; i < ndr; i++) {
xdr = ptdrifter[i].x;
ydr = ptdrifter[i].y;
ptdrifter[i].u = interp2d_spline_eval(interp_u, xdr, ydr, xa, ya);
ptdrifter[i].v = interp2d_spline_eval(interp_v, xdr, ydr, xa, ya);
}
delete[]xarr;
delete[]yarr;
gsl_interp_accel_free(xa);
gsl_interp_accel_free(ya);
interp2d_spline_free(interp_u);
interp2d_spline_free(interp_v);
}
