def write_fits(self, filename, clobber=False, length_unit=None, sky_scale=None, sky_center=None): r""" Write the PPVCube to a FITS file. Parameters ---------- filename : string The name of the file to write to. clobber : boolean, optional Whether to overwrite a file with the same name that already exists. Default False. length_unit : string, optional The units to convert the coordinates to in the file. sky_scale : tuple, optional Conversion between an angle unit and a length unit, if sky coordinates are desired, e.g. (1.0, "arcsec/kpc") sky_center : tuple, optional The (RA, Dec) coordinate in degrees of the central pixel. Must be specified with *sky_scale*. Examples -------- >>> cube.write_fits("my_cube.fits", clobber=False, ... sky_scale=(1.0,"arcsec/kpc"), sky_center=(30.,45.)) """ vunit = fits_info[self.axis_type][0] vtype = fits_info[self.axis_type][1] v_center = 0.5 * (self.vbins[0] + self.vbins[-1]).in_units(vunit).value if length_unit is None: units = str(self.ds.get_smallest_appropriate_unit(self.width)) else: units = length_unit units = sanitize_fits_unit(units) dx = self.width.in_units(units).v / self.nx dy = self.width.in_units(units).v / self.ny dv = self.dv.in_units(vunit).v w = _astropy.pywcs.WCS(naxis=3) w.wcs.crpix = [ 0.5 * (self.nx + 1), 0.5 * (self.ny + 1), 0.5 * (self.nv + 1) ] w.wcs.cdelt = [dx, dy, dv] w.wcs.crval = [0.0, 0.0, v_center] w.wcs.cunit = [units, units, vunit] w.wcs.ctype = ["LINEAR", "LINEAR", vtype] fib = FITSImageData(self.data.transpose(), fields=self.field, wcs=w) fib.update_all_headers("bunit", re.sub('()', '', str(self.proj_units))) fib.update_all_headers("btype", self.field) if sky_scale is not None and sky_center is not None: fib.create_sky_wcs(sky_center, sky_scale) fib.writeto(filename, clobber=clobber)
def write_fits(self, filename, clobber=False, length_unit=None, sky_scale=None, sky_center=None): r""" Write the PPVCube to a FITS file. Parameters ---------- filename : string The name of the file to write to. clobber : boolean, optional Whether to overwrite a file with the same name that already exists. Default False. length_unit : string, optional The units to convert the coordinates to in the file. sky_scale : tuple, optional Conversion between an angle unit and a length unit, if sky coordinates are desired, e.g. (1.0, "arcsec/kpc") sky_center : tuple, optional The (RA, Dec) coordinate in degrees of the central pixel. Must be specified with *sky_scale*. Examples -------- >>> cube.write_fits("my_cube.fits", clobber=False, ... sky_scale=(1.0,"arcsec/kpc"), sky_center=(30.,45.)) """ vunit = fits_info[self.axis_type][0] vtype = fits_info[self.axis_type][1] v_center = 0.5*(self.vbins[0]+self.vbins[-1]).in_units(vunit).value if length_unit is None: units = str(self.ds.get_smallest_appropriate_unit(self.width)) else: units = length_unit units = sanitize_fits_unit(units) dx = self.width.in_units(units).v/self.nx dy = self.width.in_units(units).v/self.ny dv = self.dv.in_units(vunit).v w = _astropy.pywcs.WCS(naxis=3) w.wcs.crpix = [0.5*(self.nx+1), 0.5*(self.ny+1), 0.5*(self.nv+1)] w.wcs.cdelt = [dx,dy,dv] w.wcs.crval = [0.0,0.0,v_center] w.wcs.cunit = [units,units,vunit] w.wcs.ctype = ["LINEAR","LINEAR",vtype] fib = FITSImageData(self.data.transpose(), fields=self.field, wcs=w) fib.update_all_headers("bunit", re.sub('()', '', str(self.proj_units))) fib.update_all_headers("btype", self.field) if sky_scale is not None and sky_center is not None: fib.create_sky_wcs(sky_center, sky_scale) fib.writeto(filename, clobber=clobber)
def write_fits(self, filename, sky_scale=None, sky_center=None, clobber=True): r""" Export images to a FITS file. Writes the SZ distortion in all specified frequencies as well as the mass-weighted temperature and the optical depth. Distance units are in kpc, unless *sky_center* and *scale* are specified. Parameters ---------- filename : string The name of the FITS file to be written. sky_scale : tuple Conversion between an angle unit and a length unit, if sky coordinates are desired, e.g. (1.0, "arcsec/kpc") sky_center : tuple, optional The (RA, Dec) coordinate in degrees of the central pixel. Must be specified with *sky_scale*. clobber : boolean, optional If the file already exists, do we overwrite? Examples -------- >>> # This example just writes out a FITS file with kpc coords >>> szprj.write_fits("SZbullet.fits", clobber=False) >>> # This example uses sky coords >>> sky_scale = (1., "arcsec/kpc") # One arcsec per kpc >>> sky_center = (30., 45., "deg") >>> szprj.write_fits("SZbullet.fits", sky_center=sky_center, sky_scale=sky_scale) """ from yt.utilities.fits_image import FITSImageData dx = self.dx.in_units("kpc") dy = dx w = _astropy.pywcs.WCS(naxis=2) w.wcs.crpix = [0.5 * (self.nx + 1)] * 2 w.wcs.cdelt = [dx.v, dy.v] w.wcs.crval = [0.0, 0.0] w.wcs.cunit = ["kpc"] * 2 w.wcs.ctype = ["LINEAR"] * 2 fib = FITSImageData(self.data, fields=self.data.keys(), wcs=w) if sky_scale is not None and sky_center is not None: fib.create_sky_wcs(sky_center, sky_scale) fib.writeto(filename, clobber=clobber)
def write_fits(self, filename, sky_scale=None, sky_center=None, clobber=True): r""" Export images to a FITS file. Writes the SZ distortion in all specified frequencies as well as the mass-weighted temperature and the optical depth. Distance units are in kpc, unless *sky_center* and *scale* are specified. Parameters ---------- filename : string The name of the FITS file to be written. sky_scale : tuple Conversion between an angle unit and a length unit, if sky coordinates are desired, e.g. (1.0, "arcsec/kpc") sky_center : tuple, optional The (RA, Dec) coordinate in degrees of the central pixel. Must be specified with *sky_scale*. clobber : boolean, optional If the file already exists, do we overwrite? Examples -------- >>> # This example just writes out a FITS file with kpc coords >>> szprj.write_fits("SZbullet.fits", clobber=False) >>> # This example uses sky coords >>> sky_scale = (1., "arcsec/kpc") # One arcsec per kpc >>> sky_center = (30., 45., "deg") >>> szprj.write_fits("SZbullet.fits", sky_center=sky_center, sky_scale=sky_scale) """ from yt.utilities.fits_image import FITSImageData dx = self.dx.in_units("kpc") dy = dx w = _astropy.pywcs.WCS(naxis=2) w.wcs.crpix = [0.5*(self.nx+1)]*2 w.wcs.cdelt = [dx.v,dy.v] w.wcs.crval = [0.0,0.0] w.wcs.cunit = ["kpc"]*2 w.wcs.ctype = ["LINEAR"]*2 fib = FITSImageData(self.data, fields=self.data.keys(), wcs=w) if sky_scale is not None and sky_center is not None: fib.create_sky_wcs(sky_center, sky_scale) fib.writeto(filename, clobber=clobber)
def test_fits_image(): tmpdir = tempfile.mkdtemp() curdir = os.getcwd() os.chdir(tmpdir) fields = ("density", "temperature") units = ( 'g/cm**3', 'K', ) ds = fake_random_ds(64, fields=fields, units=units, nprocs=16, length_unit=100.0) prj = ds.proj("density", 2) prj_frb = prj.to_frb((0.5, "unitary"), 128) fid1 = FITSImageData(prj_frb, fields=["density", "temperature"], units="cm") fits_prj = FITSProjection(ds, "z", ["density", "temperature"], image_res=128, width=(0.5, "unitary")) yield assert_equal, fid1.get_data("density"), fits_prj.get_data("density") yield assert_equal, fid1.get_data("temperature"), fits_prj.get_data( "temperature") fid1.writeto("fid1.fits", clobber=True) new_fid1 = FITSImageData.from_file("fid1.fits") yield assert_equal, fid1.get_data("density"), new_fid1.get_data("density") yield assert_equal, fid1.get_data("temperature"), new_fid1.get_data( "temperature") ds2 = load("fid1.fits") ds2.index assert ("fits", "density") in ds2.field_list assert ("fits", "temperature") in ds2.field_list dw_cm = ds2.domain_width.in_units("cm") assert dw_cm[0].v == 50. assert dw_cm[1].v == 50. slc = ds.slice(2, 0.5) slc_frb = slc.to_frb((0.5, "unitary"), 128) fid2 = FITSImageData(slc_frb, fields=["density", "temperature"], units="cm") fits_slc = FITSSlice(ds, "z", ["density", "temperature"], image_res=128, width=(0.5, "unitary")) yield assert_equal, fid2.get_data("density"), fits_slc.get_data("density") yield assert_equal, fid2.get_data("temperature"), fits_slc.get_data( "temperature") dens_img = fid2.pop("density") temp_img = fid2.pop("temperature") # This already has some assertions in it, so we don't need to do anything # with it other can just make one fid_comb = FITSImageData.from_images([dens_img, temp_img]) cut = ds.cutting([0.1, 0.2, -0.9], [0.5, 0.42, 0.6]) cut_frb = cut.to_frb((0.5, "unitary"), 128) fid3 = FITSImageData(cut_frb, fields=["density", "temperature"], units="cm") fits_cut = FITSOffAxisSlice(ds, [0.1, 0.2, -0.9], ["density", "temperature"], image_res=128, center=[0.5, 0.42, 0.6], width=(0.5, "unitary")) yield assert_equal, fid3.get_data("density"), fits_cut.get_data("density") yield assert_equal, fid3.get_data("temperature"), fits_cut.get_data( "temperature") fid3.create_sky_wcs([30., 45.], (1.0, "arcsec/kpc")) fid3.writeto("fid3.fits", clobber=True) new_fid3 = FITSImageData.from_file("fid3.fits") assert_same_wcs(fid3.wcs, new_fid3.wcs) assert new_fid3.wcs.wcs.cunit[0] == "deg" assert new_fid3.wcs.wcs.cunit[1] == "deg" assert new_fid3.wcs.wcs.ctype[0] == "RA---TAN" assert new_fid3.wcs.wcs.ctype[1] == "DEC--TAN" buf = off_axis_projection(ds, ds.domain_center, [0.1, 0.2, -0.9], 0.5, 128, "density").swapaxes(0, 1) fid4 = FITSImageData(buf, fields="density", width=100.0) fits_oap = FITSOffAxisProjection(ds, [0.1, 0.2, -0.9], "density", width=(0.5, "unitary"), image_res=128, depth_res=128, depth=(0.5, "unitary")) yield assert_equal, fid4.get_data("density"), fits_oap.get_data("density") cvg = ds.covering_grid(ds.index.max_level, [0.25, 0.25, 0.25], [32, 32, 32], fields=["density", "temperature"]) fid5 = FITSImageData(cvg, fields=["density", "temperature"]) assert fid5.dimensionality == 3 fid5.update_header("density", "time", 0.1) fid5.update_header("all", "units", "cgs") assert fid5["density"].header["time"] == 0.1 assert fid5["temperature"].header["units"] == "cgs" assert fid5["density"].header["units"] == "cgs" os.chdir(curdir) shutil.rmtree(tmpdir)
def test_fits_image(): tmpdir = tempfile.mkdtemp() curdir = os.getcwd() os.chdir(tmpdir) fields = ("density", "temperature") units = ('g/cm**3', 'K',) ds = fake_random_ds(64, fields=fields, units=units, nprocs=16, length_unit=100.0) prj = ds.proj("density", 2) prj_frb = prj.to_frb((0.5, "unitary"), 128) fid1 = FITSImageData(prj_frb, fields=["density","temperature"], units="cm") fits_prj = FITSProjection(ds, "z", ["density","temperature"], image_res=128, width=(0.5,"unitary")) yield assert_equal, fid1.get_data("density"), fits_prj.get_data("density") yield assert_equal, fid1.get_data("temperature"), fits_prj.get_data("temperature") fid1.writeto("fid1.fits", clobber=True) new_fid1 = FITSImageData.from_file("fid1.fits") yield assert_equal, fid1.get_data("density"), new_fid1.get_data("density") yield assert_equal, fid1.get_data("temperature"), new_fid1.get_data("temperature") ds2 = load("fid1.fits") ds2.index assert ("fits","density") in ds2.field_list assert ("fits","temperature") in ds2.field_list dw_cm = ds2.domain_width.in_units("cm") assert dw_cm[0].v == 50. assert dw_cm[1].v == 50. slc = ds.slice(2, 0.5) slc_frb = slc.to_frb((0.5, "unitary"), 128) fid2 = FITSImageData(slc_frb, fields=["density","temperature"], units="cm") fits_slc = FITSSlice(ds, "z", ["density","temperature"], image_res=128, width=(0.5,"unitary")) yield assert_equal, fid2.get_data("density"), fits_slc.get_data("density") yield assert_equal, fid2.get_data("temperature"), fits_slc.get_data("temperature") dens_img = fid2.pop("density") temp_img = fid2.pop("temperature") # This already has some assertions in it, so we don't need to do anything # with it other can just make one fid_comb = FITSImageData.from_images([dens_img, temp_img]) cut = ds.cutting([0.1, 0.2, -0.9], [0.5, 0.42, 0.6]) cut_frb = cut.to_frb((0.5, "unitary"), 128) fid3 = FITSImageData(cut_frb, fields=["density","temperature"], units="cm") fits_cut = FITSOffAxisSlice(ds, [0.1, 0.2, -0.9], ["density","temperature"], image_res=128, center=[0.5, 0.42, 0.6], width=(0.5,"unitary")) yield assert_equal, fid3.get_data("density"), fits_cut.get_data("density") yield assert_equal, fid3.get_data("temperature"), fits_cut.get_data("temperature") fid3.create_sky_wcs([30.,45.], (1.0,"arcsec/kpc")) fid3.writeto("fid3.fits", clobber=True) new_fid3 = FITSImageData.from_file("fid3.fits") assert_same_wcs(fid3.wcs, new_fid3.wcs) assert new_fid3.wcs.wcs.cunit[0] == "deg" assert new_fid3.wcs.wcs.cunit[1] == "deg" assert new_fid3.wcs.wcs.ctype[0] == "RA---TAN" assert new_fid3.wcs.wcs.ctype[1] == "DEC--TAN" buf = off_axis_projection(ds, ds.domain_center, [0.1, 0.2, -0.9], 0.5, 128, "density").swapaxes(0, 1) fid4 = FITSImageData(buf, fields="density", width=100.0) fits_oap = FITSOffAxisProjection(ds, [0.1, 0.2, -0.9], "density", width=(0.5,"unitary"), image_res=128, depth_res=128, depth=(0.5,"unitary")) yield assert_equal, fid4.get_data("density"), fits_oap.get_data("density") cvg = ds.covering_grid(ds.index.max_level, [0.25,0.25,0.25], [32, 32, 32], fields=["density","temperature"]) fid5 = FITSImageData(cvg, fields=["density","temperature"]) assert fid5.dimensionality == 3 fid5.update_header("density", "time", 0.1) fid5.update_header("all", "units", "cgs") assert fid5["density"].header["time"] == 0.1 assert fid5["temperature"].header["units"] == "cgs" assert fid5["density"].header["units"] == "cgs" os.chdir(curdir) shutil.rmtree(tmpdir)