graytrix

(I am not the original code developer, I just wrote the helper functions)

Graytrix is written by T. Hamana and the original page can be found here http://th.nao.ac.jp/MEMBER/hamanatk/GRayTrix/

If you use Graytrix for scientific work, please reference the following papers in which Graytrix algorithm is described:

1. Cosmological constraints from Subaru weak lensing cluster counts Takashi Hamana, Junya Sakurai, Michitaro Koike, Lance Miller PASJ, 67, 34 (2015)

2. Probing cosmology with weak lensing selected clusters I: Halo approach and all-sky simulations Masato Shirasaki, Takashi Hamana, Naoki Yoshida MNRAS, 453, 3043

Steps

1. Project all the particles (x/y/z -> vec2pix -> HEALPix maps)
2. Run make_kappaslices.py to convert shells into local convergence
   

   python make_kappaslices.py ${dir_in} ${dir_out} ${cambpar}

3. Run heal2psis.x to compute the first and second derivatives
   

   ./heal2psi.x -nside ${nside} -lmax ${lmax} -infile ${inputfilename} -outfile ${outputfile}```

4. Run graytrix.x

   ./graytrix.x -nres ${nres} -d ${outdir} -om ${omegamatter} -th ${shellwidth} -nt ${OMP_NUM_THREADS} -f ${prefix} < infile

   where
   nres: HEALPix resolution 4096->12, 8192->13
   outdir: output directory
   omegamatter: \Omega_{\rm m}
   shellwidth: width of the shells in Mpc/h
   OMP_NUM_THREAD: number of threads to use
   prefix: prefix of the output files
   

WARNING: I have been finding that ifort gives unknown spurious results resulting in random corrupted healpix files. This can be avoided by compiling with gfortran.

5. Once the outputfiles are written, one can degrade the maps:

   ./degrade_nsideout.x -infile ${infile}