void SBTopHat::SBTopHatImpl::fillXValue(tmv::MatrixView<double> val,
double x0, double dx, double dxy,
double y0, double dy, double dyx) const
{
dbg<<"SBTopHat fillXValue\n";
dbg<<"x = "<<x0<<" + i * "<<dx<<" + j * "<<dxy<<std::endl;
dbg<<"y = "<<y0<<" + i * "<<dyx<<" + j * "<<dy<<std::endl;
assert(val.stepi() == 1);
assert(val.canLinearize());
const int m = val.colsize();
const int n = val.rowsize();
typedef tmv::VIt<double,1,tmv::NonConj> It;
val.setZero();
It valit = val.linearView().begin();
for (int j=0;j<n;++j,x0+=dxy,y0+=dy) {
double x = x0;
double y = y0;
int i=0;
// Use the fact that any slice through the circle has only one segment that is non-zero.
// So start with zeroes until in the circle, then _norm, then more zeroes.
// Note: this could be sped up somewhat using the same kind of calculation we did
// for the non-sheared fillXValue (the one with izero, jzero), but I didn't
// bother. This is probably plenty fast enough for as often as the function is
// called (i.e. almost never!)
for (;i<m && (x*x+y*y > _r0sq); ++i,x+=dx,y+=dyx) ++valit;
for (;i<m && (x*x+y*y < _r0sq); ++i,x+=dx,y+=dyx) *valit++ = _norm;
for (;i<m; ++i,x+=dx,y+=dyx) ++valit;
}
}
void SBTopHat::SBTopHatImpl::fillXValue(tmv::MatrixView<double> val,
double x0, double dx, int izero,
double y0, double dy, int jzero) const
{
dbg<<"SBTopHat fillXValue\n";
dbg<<"x = "<<x0<<" + i * "<<dx<<", izero = "<<izero<<std::endl;
dbg<<"y = "<<y0<<" + j * "<<dy<<", jzero = "<<jzero<<std::endl;
assert(val.stepi() == 1);
const int m = val.colsize();
const int n = val.rowsize();
typedef tmv::VIt<double,1,tmv::NonConj> It;
val.setZero();
// The columns to consider have -r0 <= y < r0
// given that y = y0 + j dy
double absdx = std::abs(dx);
double absdy = std::abs(dy);
int j1 = std::max(0, int(std::ceil(-_r0/absdy - y0/dy)));
int j2 = std::min(n, int(std::ceil(_r0/absdy - y0/dy)));
y0 += j1 * dy;
for (int j=j1;j<j2;++j,y0+=dy) {
double ysq = y0*y0;
double xmax = std::sqrt(_r0sq - ysq);
// Set to _norm all pixels with -xmax <= x < xmax
// given that x = x0 + i dx.
int i1 = std::max(0, int(std::ceil(-xmax/absdx - x0/dx)));
int i2 = std::min(m, int(std::ceil(xmax/absdx - x0/dx)));
if (i1 < i2)
val.col(j,i1,i2).setAllTo(_norm);
}
}
void SBBox::SBBoxImpl::fillXValue(tmv::MatrixView<double> val,
double x0, double dx, int izero,
double y0, double dy, int jzero) const
{
dbg<<"SBBox fillXValue\n";
dbg<<"x = "<<x0<<" + i * "<<dx<<", izero = "<<izero<<std::endl;
dbg<<"y = "<<y0<<" + j * "<<dy<<", jzero = "<<jzero<<std::endl;
assert(val.stepi() == 1);
const int m = val.colsize();
const int n = val.rowsize();
typedef tmv::VIt<double,1,tmv::NonConj> It;
// It will be useful to do everything in units of dx,dy
x0 /= dx;
double wo2 = _wo2 / std::abs(dx);
y0 /= dy;
double ho2 = _ho2 / std::abs(dy);
xdbg<<"x0,y0 -> "<<x0<<','<<y0<<std::endl;
xdbg<<"width,height -> "<<wo2*2.<<','<<ho2*2.<<std::endl;
// Start by setting everything to zero
val.setZero();
// Then fill the interior with _norm:
// Fill pixels where:
// x0 + ix >= -width/2
// x0 + ix < width/2
// y0 + iy >= -width/2
// y0 + iy < width/2
int ix1 = std::max(0, int(std::ceil(-wo2 - x0)));
int ix2 = std::min(m, int(std::ceil(wo2 - x0)));
int iy1 = std::max(0, int(std::ceil(-ho2 - y0)));
int iy2 = std::min(n, int(std::ceil(ho2 - y0)));
if (ix1 < ix2 && iy1 < iy2)
val.subMatrix(ix1,ix2,iy1,iy2).setAllTo(_norm);
#if 0
// We used to implement this by making the pixels that cross the edge have a
// fractional flux value appropriate for the fraction of the box that goes through
// each pixel. However, this isn't actually correct. SBProfile objects are always
// rendered as the local surface brightness at the center of the pixel. To get
// the right flux, you need to convolve by a Pixel. So if someone renders a Box
// without convolving by a pixel, it is inconsistent to do this differently than we
// do all the other SBProfile types. However, since it was an involved calculation
// and someone might actually care to resurrect it in a different guise at some point,
// I'm leaving it here, just commented out.
// We need to make sure the pixels where the edges of the box fall only get
// a fraction of the flux.
//
// We divide up the range into 3 sections in x:
// left of the box where val = 0
// in the box where val = _norm
// right of the box where val = 0 again
//
// ... and 3 sections in y:
// below the box where val = 0
// in the box where val = _norm
// above the box where val = 0 again
//
// Furthermore, we have to calculate the correct values for the pixels on the border.
int ix_left, ix_right, iy_bottom, iy_top;
double x_left, x_right, y_bottom, y_top;
// Find the x edges:
double tmp = 0.5*width + 0.5;
ix_left = int(-tmp-x0+1);
ix_right = int(tmp-x0);
// If the box goes off the image, it's ok, but it will cause us problems
// later on if we don't change it. Just use ix_left = 0.
if (ix_left < 0) { ix_left = 0; x_left = 1.; }
// If the whole box is off the image, just zero and return.
else if (ix_left >= m) { val.setZero(); return; }
// Normal case: calculate the fractional flux in the edge
else x_left = tmp+x0+ix_left;
// Now the right side.
if (ix_right >= m) { ix_right = m-1; x_right = 1.; }
else if (ix_right < 0) { val.setZero(); return; }
else x_right = tmp-x0-ix_right;
xdbg<<"ix_left = "<<ix_left<<" with partial flux "<<x_left<<std::endl;
xdbg<<"ix_right = "<<ix_right<<" with partial flux "<<x_right<<std::endl;
// Repeat for y values
tmp = 0.5*height + 0.5;
iy_bottom = int(-tmp-y0+1);
iy_top = int(tmp-y0);
if (iy_bottom < 0) { iy_bottom = 0; y_bottom = 1.; }
else if (iy_bottom >= n) { val.setZero(); return; }
else y_bottom = tmp+y0+iy_bottom;
if (iy_top >= n) { iy_top = n-1; y_top = 1.; }
else if (iy_top < 0) { val.setZero(); return; }
else y_top = tmp-y0-iy_top;
xdbg<<"iy_bottom = "<<iy_bottom<<" with partial flux "<<y_bottom<<std::endl;
xdbg<<"iy_top = "<<iy_top<<" with partial flux "<<y_top<<std::endl;
xdbg<<"m,n = "<<m<<','<<n<<std::endl;
// Now we need to fill the matrix with the appropriate values in each section.
// Start with the zeros:
if (0 < ix_left)
val.subMatrix(0,ix_left,iy_bottom,iy_top+1).setZero();
if (ix_right+1 < m)
val.subMatrix(ix_right+1,m,iy_bottom,iy_top+1).setZero();
if (0 < iy_bottom)
val.colRange(0,iy_bottom).setZero();
if (iy_top+1 < n)
val.colRange(iy_top+1,n).setZero();
// Then the interior:
if (ix_left+1 < ix_right && iy_bottom+1 < iy_top)
val.subMatrix(ix_left+1,ix_right,iy_bottom+1,iy_top).setAllTo(_norm);
// And now the edges:
if (ix_left+1 < ix_right) {
val.col(iy_bottom,ix_left+1,ix_right).setAllTo(y_bottom * _norm);
val.col(iy_top,ix_left+1,ix_right).setAllTo(y_top * _norm);
}
if (iy_bottom+1 < iy_top) {
val.row(ix_left,iy_bottom+1,iy_top).setAllTo(x_left * _norm);
val.row(ix_right,iy_bottom+1,iy_top).setAllTo(x_right * _norm);
}
// Finally the corners
val(ix_left,iy_bottom) = x_left * y_bottom * _norm;
val(ix_right,iy_bottom) = x_right * y_bottom * _norm;
val(ix_left,iy_top) = x_left * y_top * _norm;
val(ix_right,iy_top) = x_right * y_top * _norm;
#endif
}
