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Problem with triangular plot: contour levels must be increas

Posted: November 17 2017
by Sunny Vagnozzi
Hi Antony et al.,

after having run getdist on my chains, I try to plot a triangular plot with the root_tri.py script, but I get
ValueError: filled contour levels must be increasing
which prevents the triangular plot from being drawn.

Any idea what might be causing this and how to fix it?

Cheers,
Sunny

Re: Problem with triangular plot: contour levels must be inc

Posted: November 17 2017
by Antony Lewis
Not sure, did this change in a recent matplotlib update, or is it specific to the chain outputs that you have? (eg. try it on a Planck chain)
Do you also get this using the GetDist gui/python scripts?

Problem with triangular plot: contour levels must be increas

Posted: November 17 2017
by Sunny Vagnozzi
It's specific to my chains, no problem with e.g. Planck chains. I suspect it might be that the chains haven't converged properly (e.g. I notice that the 1D posterior on one of the parameters is almost flat on the prior range [0,1] I imposed but with some wiggles which make its posterior non-monotonic). Could that be a problem?

Re: Problem with triangular plot: contour levels must be inc

Posted: November 17 2017
by Antony Lewis
Possibly, I'd look at the coloured scatter (3D) plots instead.

Problem with triangular plot: contour levels must be increas

Posted: November 19 2017
by Bob Zou
Hi,
I once came across this issues, too. This is my experience, hope helps.
(1) not enough steps of your chains, waiting for more steps
(2) maybe there are bugs for the getdist you used. This is my case.
Following
https://github.com/cmbant/getdist/commi ... d0a767a4e6 I solved the issues "contour levels must be increasing".

Good Luck.