/* This routine uses the LTV and LTM keyword values to compute the corner
   location and pixel size.  For the MAMA detectors, the corner location
   and pixel size are in units of high-res pixels, in contrast to the
   header keywords CENTERA1, SIZAXIS1, etc.

   ltm[0] and ltm[1] are assumed to be greater than zero.
*/

# define NINT(x)  ((x >= 0.) ? (int) (x + 0.5) : (int) (x - 0.5))

int FromLT (int rsize, double *ltm, double *ltv, int *bin, int *corner) {

/* arguments:
int rsize        i: reference pixel size, 1 or 2
double ltm[2]    i: diagonal elements of MWCS matrix
double ltv[2]    i: MWCS linear transformation vector
int bin[2]       o: pixel size in X and Y
int corner[2]    o: corner of subarray in X and Y
*/

	double dbinx, dbiny, dxcorner, dycorner;

	dbinx = (double)rsize / ltm[0];
	dbiny = (double)rsize / ltm[1];

	dxcorner = (dbinx - rsize) / 2. - dbinx * ltv[0];
	dycorner = (dbiny - rsize) / 2. - dbiny * ltv[1];

	/* Round off to the nearest integer. */
	corner[0] = NINT (dxcorner);
	corner[1] = NINT (dycorner);
	bin[0] = NINT (dbinx);
	bin[1] = NINT (dbiny);

	return (0);
}