diff options
| -rw-r--r-- | fg21sim/utils/io.py | 45 |
1 files changed, 30 insertions, 15 deletions
diff --git a/fg21sim/utils/io.py b/fg21sim/utils/io.py index c8fb20e..cd98ff7 100644 --- a/fg21sim/utils/io.py +++ b/fg21sim/utils/io.py @@ -220,7 +220,8 @@ def write_fits_image(outfile, image, header=None, float32=True, def read_fits_healpix(filename): - """Read the HEALPix map from a FITS file or a BinTableHDU to 1D array + """ + Read the HEALPix map from a FITS file or a BinTableHDU to 1D array in *RING* ordering. Parameters @@ -240,7 +241,7 @@ def read_fits_healpix(filename): ---- This function wraps on `healpy.read_map()`, but set the data type of data array to its original value as in FITS file, as well as return - FITS header as `~astropy.io.fits.Header` instance. + the header of input FITS file. """ if isinstance(filename, fits.BinTableHDU): hdu = filename @@ -254,9 +255,10 @@ def read_fits_healpix(filename): return (data.astype(dtype), header) -def write_fits_healpix(filename, hpmap, header=None, clobber=False, - checksum=False): - """Write the HEALPix map to a FITS file with proper header as well +def write_fits_healpix(outfile, hpmap, header=None, float32=True, + clobber=False, checksum=False): + """ + Write the HEALPix map to a FITS file with proper header as well as the user-provided header. This function currently only support one style of HEALPix with the @@ -269,34 +271,46 @@ def write_fits_healpix(filename, hpmap, header=None, clobber=False, Parameters ---------- - filename : str + outfile : str Filename of the output file to write the HEALPix map data hpmap : 1D `~numpy.ndarray` 1D array containing the HEALPix map data, and the ordering scheme should be "RING"; - The data type is preserved in the output FITS file. + The data type is preserved or cast into single/float32 if the + below ``float32`` parameter is True, in the output FITS file. header : `~astropy.io.fits.Header`, optional Extra header to be appended to the output FITS + float32 : bool, optional + Whether coerce the image data (generally double/float64 data type) + into single/float32 (in order to save space)? + Default: True clobber : bool, optional - Whether overwrite the existing file? + Whether to overwrite the existing output file? + Default: False checksum : bool, optional - Whether calculate the checksum for the output file, which is - recorded as the "CHECKSUM" header keyword. + Whether to calculate the data checksum, which may cost some time? + Default: False NOTE ---- - This function is intended to replace the most common case of `healpy.write_map()`, which still uses some deprecated functions of - `numpy` and `astropy`, meanwhile, it interface/arguments is not very + `numpy` and `astropy`, meanwhile, its interface/arguments is not very handy. - This function (currently) only implement the very basic feature of the `healpy.write_map()`. """ + _create_dir(outfile) + _check_existence(outfile, clobber=clobber, remove=True) + hpmap = np.asarray(hpmap) if hpmap.ndim != 1: raise ValueError("Invalid HEALPix data: only support 1D array") - # Hack to ignore the dtype byteorder, use native endianness - dtype = np.dtype(hpmap.dtype.type) + if float32: + dtype = np.float32 + else: + # HACK: ignore the dtype byteorder, use native endianness + dtype = np.dtype(hpmap.dtype.type) hpmap = hpmap.astype(dtype) # npix = hpmap.size @@ -326,9 +340,10 @@ def write_fits_healpix(filename, hpmap, header=None, clobber=False, # Merge user-provided header # NOTE: use the `.extend()` method instead of `.update()` method if header is not None: - hdr.extend(fits.Header(header)) + hdr.extend(header, update=True) # hdu = fits.BinTableHDU.from_columns([ fits.Column(name="I", array=hpmap, format=colfmt) ], header=hdr) - hdu.writeto(filename, clobber=clobber, checksum=checksum) + hdu.writeto(outfile, checksum=checksum) + logger.info("Wrote HEALPix map to FITS file: %s" % outfile) |