CosmoMC - GetDist: NaN in plot_data 2D files
Posted: March 09 2016
Just wanted to point out that when I run getdist with distparams.ini to create 2D plots, the files generated in plot_data directory are always full of NaN. This only happens with 2D files (root_2D_param1_param2) and not with 1D files (root_p_param.dat).
If I use the parameter file disttest.ini instead, the problem seems to be solved. I was puzzled by this, then I realized that distparams.ini defaults are contained in the file "python/getdist/analysis_defaults.ini" whereas disttest.ini defaults are linked to "batch2/getdist_common.ini". In the former, the setting "smooth_scale_2D" is set to -1, where a negative value is interpreted as an "automatic smoothing length" which depends on the parameter. In the latter, that same setting is set to 2, which seems to work.
Using GetDist GUI with Planck public chains I sometimes see some glitches when rendering 2D plots, which I have solved by going to "Options" then "Analysis Settings" and then changing the value of "smooth_scale_2D" to 2. For example, if you plot mnu vs. H0 using the chains base_nnu_mnu_plikHM_TTTEEE_lowTEB and base_nnu_mnu_plikHM_TTTEEE_lowTEB_post_H070p6, the former (the one without postprocessing) will be rendered with glitches, which are gone after setting "smooth_scale_2D" to 2.
Not sure if I am the only one having this problem, but if confirmed, I think the default value of "smooth_scale_2D" should be set back to 2 to avoid this issue, or instead, the automatic smoothing length algorithm should be revised. Thanks a lot!
If I use the parameter file disttest.ini instead, the problem seems to be solved. I was puzzled by this, then I realized that distparams.ini defaults are contained in the file "python/getdist/analysis_defaults.ini" whereas disttest.ini defaults are linked to "batch2/getdist_common.ini". In the former, the setting "smooth_scale_2D" is set to -1, where a negative value is interpreted as an "automatic smoothing length" which depends on the parameter. In the latter, that same setting is set to 2, which seems to work.
Using GetDist GUI with Planck public chains I sometimes see some glitches when rendering 2D plots, which I have solved by going to "Options" then "Analysis Settings" and then changing the value of "smooth_scale_2D" to 2. For example, if you plot mnu vs. H0 using the chains base_nnu_mnu_plikHM_TTTEEE_lowTEB and base_nnu_mnu_plikHM_TTTEEE_lowTEB_post_H070p6, the former (the one without postprocessing) will be rendered with glitches, which are gone after setting "smooth_scale_2D" to 2.
Not sure if I am the only one having this problem, but if confirmed, I think the default value of "smooth_scale_2D" should be set back to 2 to avoid this issue, or instead, the automatic smoothing length algorithm should be revised. Thanks a lot!