void
_nrrdMeasureLineFit(double *intc, double *slope,
const void *line, int lineType, size_t len,
double axmin, double axmax) {
double x, y, xi=0, yi=0, xiyi=0, xisq=0, det, (*lup)(const void*, size_t);
size_t ii;
lup = nrrdDLookup[lineType];
if (!( AIR_EXISTS(axmin) && AIR_EXISTS(axmax) )) {
axmin = 0;
axmax = len-1;
}
if (1 == len) {
*slope = 0;
*intc = lup(line, 0);
} else {
for (ii=0; ii<len; ii++) {
x = NRRD_NODE_POS(axmin, axmax, len, ii);
y = lup(line, ii);
xi += x;
yi += y;
xiyi += x*y;
xisq += x*x;
}
det = len*xisq - xi*xi;
*slope = (len*xiyi - xi*yi)/det;
*intc = (-xi*xiyi + xisq*yi)/det;
}
}
/*
** Thu Dec 13 02:25:12 EST 2007:
** this had no use outside gage, added _ prefix
*/
void
_gageShapeUnitItoW(gageShape *shape, double world[3], double index[3]) {
int i;
if (nrrdCenterNode == shape->center) {
for (i=0; i<=2; i++) {
world[i] = NRRD_NODE_POS(-shape->volHalfLen[i], shape->volHalfLen[i],
shape->size[i], index[i]);
}
} else {
for (i=0; i<=2; i++) {
world[i] = NRRD_CELL_POS(-shape->volHalfLen[i], shape->volHalfLen[i],
shape->size[i], index[i]);
}
}
}
static void
shapeUnitItoW(const gageShape *shape, double world[3],
const double indx[3], const double volHalfLen[3]) {
unsigned int i;
if (nrrdCenterNode == shape->center) {
for (i=0; i<=2; i++) {
world[i] = NRRD_NODE_POS(-volHalfLen[i], volHalfLen[i],
shape->size[i], indx[i]);
}
} else {
for (i=0; i<=2; i++) {
world[i] = NRRD_CELL_POS(-volHalfLen[i], volHalfLen[i],
shape->size[i], indx[i]);
}
}
}
void
_nrrdMeasureLineError(void *ans, int ansType,
const void *line, int lineType, size_t len,
double axmin, double axmax) {
double x, y, slope, intc, tmp, err=0, (*lup)(const void*, size_t);
size_t ii;
_nrrdMeasureLineFit(&intc, &slope, line, lineType, len, axmin, axmax);
if (!( AIR_EXISTS(axmin) && AIR_EXISTS(axmax) )) {
axmin = 0;
axmax = len-1;
}
lup = nrrdDLookup[lineType];
for (ii=0; ii<len; ii++) {
x = NRRD_NODE_POS(axmin, axmax, len, ii);
y = lup(line, ii);
tmp = slope*x + intc - y;
err += tmp*tmp;
}
nrrdDStore[ansType](ans, err);
}
