First, read the Caveats regarding the interpretation of results produced by DecompIR.
Then, if you are happy:
Download the latest version of DecompIR from this page.
This latest version is v1.2. After any future updates, this version will still be available through the Revision History subpage.
After downloading, untar the package. The package will contain 11 IDL *.pro files, one *.dat file and three directories: Draine, Filters and Hosts. Place all these files and directories together in the same directory somewhere in your IDL path, e.g.
> ls /path/to/my/idl/routines/decompir/
Draine
Filters
Hosts
broken_pl_bb.pro
decompir_buildfit.pro
decompir_chisq.pro
decompir_example.pro
decompir_flux.pro
decompir_func.pro
decompir_get_templates.pro
decompir_initial_guess.pro
decompir_sendout.pro
decompir.pro
example.dat
int_over_resp.pro
You can test whether the package works using the decompir_example procedure. This performs a simple fit to check whether you have all the necessary procedures in your IDL path (the actual fit isn't good, but that's not the point here).
Remember, please read the Caveats regarding the interpretation of results produced by DecompIR.
Download:
v1.21 - Multiplied the value in the output.total and output.mir_total by a factor of (1.+z) which means that the flux given is ACTUAL rest frame (in previous versions it was int(rest_freq, obs_flux). To calculate rest frame luminosities, you should now multiply total flux by 4*Pi*R2/(1+z)2, where R is the luminosity distance. The manual has been updated to reflect these changes.