Problem with triangular plot: contour levels must be increasing

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
Post Reply
Sunny Vagnozzi
Posts: 43
Joined: August 15 2016
Affiliation: Oskar Klein Centre, Stockholm University

Problem with triangular plot: contour levels must be increas

Post by Sunny Vagnozzi » November 17 2017

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

Antony Lewis
Posts: 1393
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

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

Post by Antony Lewis » November 17 2017

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?

Sunny Vagnozzi
Posts: 43
Joined: August 15 2016
Affiliation: Oskar Klein Centre, Stockholm University

Problem with triangular plot: contour levels must be increas

Post by Sunny Vagnozzi » November 17 2017

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?

Antony Lewis
Posts: 1393
Joined: September 23 2004
Affiliation: University of Sussex
Contact:

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

Post by Antony Lewis » November 17 2017

Possibly, I'd look at the coloured scatter (3D) plots instead.

Bob Zou
Posts: 5
Joined: July 21 2016
Affiliation: Beijing Institute of Technology

Problem with triangular plot: contour levels must be increas

Post by Bob Zou » November 19 2017

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.

Post Reply