13. Crosswalk¶
Comparing functionality in NEMO with like-wise programs in other packages can be helpful for onboarding. Here are a few examples:
NEMO |
python |
CASA |
MIRIAD |
|---|---|---|---|
tabtrend |
numpy.diff() |
N/A |
N/A |
tabplot |
plt.plot() |
N/A |
N/A |
tabhist |
plt.hist() |
N/A |
N/A |
fitsccd |
hdu=astropy.io.fits.open() |
importfits() |
fits op=xyin |
ccdfits |
hdu=astropy.io.fits.open() |
exportfits() |
fits op=xyout |
ccdprint |
print(hdu[0].data) |
??? |
imlist |
ccdmom |
numpy.sum() |
immoments() |
moment |
ccdmath |
numpy |
immath() |
maths |
ccdstat |
hdu[0].data.std() |
imstat() |
imstat |
ccdplot |
numpy.contour |
imview() |
implot,cgdisp |
The CASA users guide has a more expanded table of this, just comparing CASA with MIRIAD and CLICK. There it is called a CASA-MIRIAD and CASA-CLIC dictionary.
13.1. Example¶
An expanded example how to read a FITS (image) into the respective systems is as follows, plus some sample commands one can in the respective package:
# NEMO
$ fitsccd ngc0001.fits ngc0001.ccd
$ ccdhead ngc0001.ccd
$ ccdplot ngc0001.ccd yapp=/xs
# PYTHON
In [1]: hdu = astropy.io.fits.open('ngc0001.fits')
In [2]: print(hdu[0].header)
In [2]: plt.imshow(hdu[0].data)
# CASA
CASA <1>: importfits('ngc0001.fits', 'ngc0001.im')
CASA <2>: imhead('ngc0001.im')
CASA <2>: imview('ngc0001.im')
# MIRIAD
$ fits in=ngc0001.fits out=ngc0001.mir op=xyin
$ imhead in=ngc0001.mir
$ implot in=ngc0001.mir device=/xs