diff options
Diffstat (limited to 'astro/fits/fitscube.py')
| -rwxr-xr-x | astro/fits/fitscube.py | 78 |
1 files changed, 44 insertions, 34 deletions
diff --git a/astro/fits/fitscube.py b/astro/fits/fitscube.py index 3d2d4d0..0ad2009 100755 --- a/astro/fits/fitscube.py +++ b/astro/fits/fitscube.py @@ -33,23 +33,28 @@ class FITSCube: print("Loaded FITS cube from file: %s" % infile) print("Cube dimensions: %dx%dx%d" % (self.width, self.height, self.nslice)) + # The Z-axis position of the first slice. + self.zbegin = self.header["CRVAL3"] + # The Z-axis step/spacing between slices. + self.zstep = self.header["CDELT3"] def add_slices(self, slices, zbegin=0.0, zstep=1.0): """ Create a FITS cube from input image slices. """ + self.slices = slices + self.zbegin = zbegin + self.zstep = zstep nslice = len(slices) header, image = self.open_image(slices[0]) shape = (nslice, ) + image.shape data = np.zeros(shape, dtype=image.dtype) for i, s in enumerate(slices): - print("[%d/%d] Adding image slice: %s ..." % (i, nslice, s)) + print("[%d/%d] Adding image slice: %s ..." % (i+1, nslice, s)) hdr, img = self.open_image(s) data[i, :, :] = img self.data = data - wcs = self.make_wcs(header, zbegin=zbegin, zstep=zstep) self.header = header.copy(strip=True) - self.header.extend(wcs.to_header(), update=True) print("Created FITS cube of dimensions: %dx%dx%d" % (self.width, self.height, self.nslice)) @@ -63,7 +68,7 @@ class FITSCube: The input slice image may have following dimensions: * NAXIS=2: [Y, X] * NAXIS=3: [FREQ=1, Y, X] - * NAXIS=4: [FREQ=1, STOKES=1, Y, X] + * NAXIS=4: [STOKES=1, FREQ=1, Y, X] NOTE ---- @@ -86,31 +91,50 @@ class FITSCube: # NAXIS=3: [FREQ=1, Y, X] image = data[0, :, :] elif data.ndim == 4 and data.shape[0] == 1 and data.shape[1] == 1: - # NAXIS=4: [FREQ=1, STOKES=1, Y, X] + # NAXIS=4: [STOKES=1, FREQ=1, Y, X] image = data[0, 0, :, :] else: raise ValueError("Slice '{0}' has invalid dimensions: {1}".format( infile, data.shape)) return (header, image) - def make_wcs(self, header, zbegin, zstep): + @property + def header(self): + try: + return self.header_ + except AttributeError: + return fits.Header() + + @header.setter + def header(self, value): + self.header_ = value + for key in ["CTYPE4", "CRPIX4", "CRVAL4", "CDELT4", "CUNIT4"]: + try: + del self.header_[key] + except KeyError: + pass + + @property + def wcs(self): w = WCS(naxis=3) w.wcs.ctype = ["pixel", "pixel", "pixel"] - w.wcs.crpix = np.array([header.get("CRPIX1", 1.0), - header.get("CRPIX2", 1.0), + w.wcs.crpix = np.array([self.header.get("CRPIX1", 1.0), + self.header.get("CRPIX2", 1.0), 1.0]) - w.wcs.crval = np.array([header.get("CRVAL1", 0.0), - header.get("CRVAL2", 0.0), - zbegin]) - w.wcs.cdelt = np.array([header.get("CDELT1", 1.0), - header.get("CDELT2", 1.0), - zstep]) + w.wcs.crval = np.array([self.header.get("CRVAL1", 0.0), + self.header.get("CRVAL2", 0.0), + self.zbegin]) + w.wcs.cdelt = np.array([self.header.get("CDELT1", 1.0), + self.header.get("CDELT2", 1.0), + self.zstep]) return w - def write(self, outfile, clobber): - self.header.add_history(datetime.now().isoformat()) - self.header.add_history(" ".join(sys.argv)) - hdu = fits.PrimaryHDU(data=self.data, header=self.header) + def write(self, outfile, clobber=False): + header = self.header + header.extend(self.wcs.to_header(), update=True) + header.add_history(datetime.now().isoformat()) + header.add_history(" ".join(sys.argv)) + hdu = fits.PrimaryHDU(data=self.data, header=header) try: hdu.writeto(outfile, overwrite=clobber) except TypeError: @@ -132,26 +156,12 @@ class FITSCube: return ns @property - def zbegin(self): - """ - The Z-axis position of the first slice. - """ - return self.header["CRVAL3"] - - @property - def zstep(self): - """ - The Z-axis step/spacing between slices. - """ - return self.header["CDELT3"] - - @property def zvalues(self): """ Calculate the Z-axis positions for all slices """ nslice = self.nslice - wcs = WCS(self.header) + wcs = self.wcs pix = np.zeros(shape=(nslice, 3), dtype=np.int) pix[:, 2] = np.arange(nslice) world = wcs.wcs_pix2world(pix, 0) @@ -166,7 +176,7 @@ def cmd_info(args): print("Image/slice size: %dx%d" % (cube.width, cube.height)) print("Number of slices: %d" % cube.nslice) print("Slice step/spacing: %.3f" % cube.zstep) - print("Slice positions: {0}".format(cube.zvalues)) + print("Slice positions:\n{0}".format(cube.zvalues)) def cmd_create(args): |