@qinhanmin2014 do you want just the modules/tree.rst updated to include this dependency or is there other documents that need this added as well?

I can't see anywhere where we obviously state the requirements for running
examples, which should also include versions. I vote for including it in
doc/install.rst

@jnothman readme?
For running the examples Matplotlib >= 1.5.1 is required. A few examples require scikit-image >= 0.12.3, a few examples require pandas >= 0.18.0 and a few example require joblib >= 0.11.

I only suggest install.rst because other dependency versions are listed there

I mean we obviously state the requirements for running examples in README.rst and I think that's enough. If you want to copy it to install.rst, let's do it.

Ok. Will do it later tonight.

@maftabali can we pass this onto someone else?

@jnothman sorry, been snowed under. Do you want this just in the readme or in the install.rst as well?

README is fine. You're welcome to say someone else should take it.

@jnothman If it needs doing straight away, please feel free to pass it someone else as it will take me a while to get to it.

(2) We need to install matplotlib in CIs

Not all CIs though -- as it's still an optional dependency, and we want to check that tests can run without it.

FYI, we added matplotlib checks for the pylatest_conda CI env in #12599