Iraf in Microns?
Barbara Rojas wrote on Jan 23, 2008
Hi!
I have some ascii files in micron units. I converted them in .fits files using the task 'rspectext' in the oned package and when I plotted them with splot I realized that it assumed that the unit of wavelength was angstroms. I know I can multiply my wavelenghts in the ascii file by 10^4 and then get angstroms and then in splot type :units microns if I want to see the spectrum in microns but (since I'm lazy :)) I was wondering if there is a way to make iraf work in microns (by default):?: I checked the rspectext task but there's no choice there to put the wavelength format (like in wspectext)
Thanks!
B
I have some ascii files in micron units. I converted them in .fits files using the task 'rspectext' in the oned package and when I plotted them with splot I realized that it assumed that the unit of wavelength was angstroms. I know I can multiply my wavelenghts in the ascii file by 10^4 and then get angstroms and then in splot type :units microns if I want to see the spectrum in microns but (since I'm lazy :)) I was wondering if there is a way to make iraf work in microns (by default):?: I checked the rspectext task but there's no choice there to put the wavelength format (like in wspectext)
Thanks!
B
Francisco Valdes wrote on Jan 23, 2008
Hi,
The spectral packages, such as onedspec, have heuristics that try and handle units and recognize various keywords for the dispersion units. In your case you should be able to add a keyword CUNIT1 (or whatever axis is the wavelength) with a value of 'micron'. Note that CUNITn is not standard FITS though its meaning would be quite clear.
Once the software knows the units there are ways to change the units in various tasks. Note that SPLOT will plot in angstroms by default. There is a parameter in SPLOT to specify the desired default units. Note also the ":units" command to change units. This also appears in other tasks.
Yours,
Frank Valdes
The spectral packages, such as onedspec, have heuristics that try and handle units and recognize various keywords for the dispersion units. In your case you should be able to add a keyword CUNIT1 (or whatever axis is the wavelength) with a value of 'micron'. Note that CUNITn is not standard FITS though its meaning would be quite clear.
Once the software knows the units there are ways to change the units in various tasks. Note that SPLOT will plot in angstroms by default. There is a parameter in SPLOT to specify the desired default units. Note also the ":units" command to change units. This also appears in other tasks.
Yours,
Frank Valdes
Barbara Rojas wrote on Jan 23, 2008
Sweet! thanks!
B
B
Last post on Jan 23, 2008