@tacaswell you asked for me to add a "whats new" entry and and "example". More than happy to do so, but not quite clear on how. For the example, something under examples/axes_grid1 ? But I have no idea where the "whats new" should go.

I also note the above is not squashed properly. Working on it ;-)

Thanks, Jody

whats new entry goes in https://github.com/matplotlib/matplotlib/tree/master/doc/users/whats_new (see readme file) and is a quick blurb advertising the new feature.

I think that is a good place for the example. If you are up for it, a longer tutorial showing the (many) ways to set up color bar axes would be great too!

@tacaswell

OK, I actually think that this should be closed and dropped.

I tricked myself into thinking that this worked with tight_layout(), but writing the test cases proved that was not the case.

The fundamental problem, I think, is that tight_layout() really only gives new subplot spacing parameters appropriate for one gridspec, whereas this creates three distinct gridspecs that don't really know about each other. So tight_layout can't suggest useful padding in the vertical or horizontal.

The previous change, #8739, is still useful, and I suggest is superior because it throws a warning when tight_layout() is called.

I guess this hearkens back to #1109. There needs to be ways to group artists together, and then let them expand or contract recursively to fill the space assigned to them. I have trouble even wrapping my head around how that would look.

You are describing a layout manager which can be done with a linear constraint solver (ex https://github.com/nucleic/kiwi). This is basically what tight_layout does, but more general.

OK, closing this for now. I have another idea to do something similar using gridspec...