/* zscore - z-score differences */
double do_int_calcs(double f_px, double s_px, double mean_f_px, double mean_s_px, double sum_f_px, double sum_s_px, double nvox){
double sd_f, sd_s, zscore;
/* mean */
mean_f_px = sum_f_px / nvox;
mean_s_px = sum_s_px / nvox;
/* variance and sd */
sd_f = sqrt(((nvox * SQR2(sum_f_px)) - SQR2(f_px)) / (nvox * (nvox - 1)));
sd_s = sqrt(((nvox * SQR2(sum_s_px)) - SQR2(s_px)) / (nvox * (nvox - 1)));
for (int i = 0; i < nvox; i ++) {
zscore += fabs((f_px - mean_f_px)/sd_f - (s_px - mean_s_px)/sd_s)/nvox;
}
return zscore;
}
/* regrid a point in a file using the input co-ordinate and data */
void regrid_point(VIO_Volume * totals, VIO_Volume * weights,
double x, double y, double z, int v_size, double *data_buf)
{
int sizes[MAX_VAR_DIMS];
VIO_Real steps[MAX_VAR_DIMS];
VIO_Real starts[MAX_VAR_DIMS];
int start_idx[3];
int stop_idx[3];
double value, weight;
double euc_dist;
double euc[3];
double c_pos[3];
int i, j, k, v;
double coord[3]; /* target point in mm coordinates, in X, Y, Z order */
VIO_Transform dircos, invdircos;
VIO_Vector vector;
VIO_Real dir[3];
/* the coord used below has to be in mm coordinates in the dircos space of the
target volume. Hence the manipulations with the vols direction_cosines */
make_identity_transform(&dircos);
get_volume_direction_cosine(*totals, perm[0], dir);
fill_Vector(vector, dir[0], dir[1], dir[2]);
set_transform_x_axis(&dircos, &vector);
get_volume_direction_cosine(*totals, perm[1], dir);
fill_Vector(vector, dir[0], dir[1], dir[2]);
set_transform_y_axis(&dircos, &vector);
get_volume_direction_cosine(*totals, perm[2], dir);
fill_Vector(vector, dir[0], dir[1], dir[2]);
set_transform_z_axis(&dircos, &vector);
for(i = 0; i < 4; i++){
for(j = 0; j < 4; j++){
Transform_elem(invdircos, i, j) = Transform_elem(dircos, j, i);
}
}
transform_point(&invdircos, x, y, z, &coord[0], &coord[1], &coord[2]);
get_volume_sizes(*totals, sizes); /* in volume voxel order, ie z,y,x with x fastest */
get_volume_separations(*totals, steps);
get_volume_starts(*totals, starts);
/* figure out the neighbouring voxels start and stop (in voxel co-ordinates) */
for(i = 0; i < 3; i++){ /* go through x, y and z */
start_idx[i] =
(int)rint((coord[i] - starts[perm[i]] - regrid_radius[i]) / steps[perm[i]]);
stop_idx[i] = start_idx[i] + rint((regrid_radius[i] * 2) / steps[perm[i]]);
/* flip if required */
if(start_idx[i] > stop_idx[i]){
value = start_idx[i];
start_idx[i] = stop_idx[i];
stop_idx[i] = value;
}
/* check that we aren't off the edge */
if(start_idx[i] < 0){
start_idx[i] = 0;
}
if(stop_idx[i] >= sizes[perm[i]]){
stop_idx[i] = sizes[perm[i]] - 1;
}
}
/* loop over the neighbours, getting euclidian distance */
c_pos[0] = starts[perm[0]] + (start_idx[0] * steps[perm[0]]);
for(i = start_idx[0]; i <= stop_idx[0]; i++){
euc[0] = fabs(c_pos[0] - coord[0]);
c_pos[1] = starts[perm[1]] + (start_idx[1] * steps[perm[1]]);
for(j = start_idx[1]; j <= stop_idx[1]; j++){
euc[1] = fabs(c_pos[1] - coord[1]);
c_pos[2] = starts[perm[2]] + (start_idx[2] * steps[perm[2]]);
for(k = start_idx[2]; k <= stop_idx[2]; k++){
euc[2] = fabs(c_pos[2] - coord[2]);
euc_dist = sqrt(SQR2(euc[0]) + SQR2(euc[1]) + SQR2(euc[2]));
if((regrid_radius[0] == 0 || euc[0] <= regrid_radius[0]) &&
(regrid_radius[1] == 0 || euc[1] <= regrid_radius[1]) &&
(regrid_radius[2] == 0 || euc[2] <= regrid_radius[2])){
/* calculate the weighting factor */
switch (regrid_type){
default:
fprintf(stderr, "Erk! unknown regrid_type. File: %s Line: %d\n",
__FILE__, __LINE__);
exit(EXIT_FAILURE);
break;
case NEAREST_FUNC:
case LINEAR_FUNC:
weight = euc_dist;
break;
case KAISERBESSEL_FUNC:
weight =
gsl_sf_bessel_I0(regrid_sigma[0] *
sqrt(1 - SQR2(euc[0] / regrid_radius[0]))) *
gsl_sf_bessel_I0(regrid_sigma[1] *
sqrt(1 - SQR2(euc[1] / regrid_radius[1]))) *
gsl_sf_bessel_I0(regrid_sigma[2] *
sqrt(1 - SQR2(euc[2] / regrid_radius[2]))) /
SQR3((regrid_radius[0] + regrid_radius[1] + regrid_radius[2]) / 3);
break;
case GAUSSIAN_FUNC:
weight = exp(-SQR2(euc[0]) / SQR2(regrid_sigma[0])) *
exp(-SQR2(euc[1]) / SQR2(regrid_sigma[1])) *
exp(-SQR2(euc[2]) / SQR2(regrid_sigma[2]));
break;
}
/* set data values */
if(regrid_type == NEAREST_FUNC){
value = get_volume_real_value(*weights, k, j, i, 0, 0);
if(weight < value){
set_volume_real_value(*weights, k, j, i, 0, 0, weight);
for(v = 0; v < v_size; v++){
set_volume_real_value(*totals, k, j, i, v, 0,
data_buf[0 + v] * weight);
}
}
}
else{
for(v = 0; v < v_size; v++){
value = get_volume_real_value(*totals, k, j, i, v, 0);
set_volume_real_value(*totals, k, j, i, v, 0,
value + (data_buf[0 + v] * weight));
}
/* increment count value */
value = get_volume_real_value(*weights, k, j, i, 0, 0);
set_volume_real_value(*weights, k, j, i, 0, 0, value + weight);
}
}
c_pos[2] += steps[perm[2]];
}
c_pos[1] += steps[perm[1]];
}
c_pos[0] += steps[perm[0]];
}
}
