Single legend for gridspace

BMM3 · March 29, 2024, 3:57pm

I’m trying to create a a gridspace with NdOverlays in each tile.
As can be seen in the figure below, it is showing the legend for each figure and therefore the “gridCol” is not shown properly.
It would be better if I can have 1 single legend for all the plots in the gridspace. However, setting the “show_legend=True” for the gridspace doesn’t do anything.

According to the following issue it should be possible, right?

github.com/holoviz/holoviews

Enable single legend for `NdLayout` (instead of multiple identical legends in each subplot)

opened 05:52PM - 04 Dec 15 UTC

closed 08:51PM - 04 Dec 15 UTC

maxalbert

type: feature tag: backend: bokeh tag: backend: mpl

The code snippet below creates an `NdLayout` object with multiple sub-panels, ea…ch of which is displayed with its own legend (see screenshot). However, all these legends are identical. It would be great to be able to attach a single legend to the top-level `NdLayout` instead of multiple ones to the individual sub-plots. This probably also applies to `GridSpace`, although I can't get legends to work with `GridSpace` at the moment so don't know how it handles them. I wonder whether it would make sense to also allow "sharing" of other properties (such as axis labels/ticks, etc.) between sub-plots. However, I'm not sure whether this is covered by the existence of `GridSpace` because I don't fully understand the relation and difference between `NdLayout` and `GridSpace`. ![sample_ndlayout](https://cloud.githubusercontent.com/assets/2692805/11594800/e3c5bb98-9aa3-11e5-890c-179bf7bc0c1d.png) ``` python %reload_ext holoviews.ipython from holoviews import * import holoviews as hv import numpy as np import itertools phases = np.linspace(0, np.pi, 5) freqs = [10, 15] shifts = [0, 0.5] def make_curve(phase, freq, shift): x = np.linspace(-0.5, 0.5, 202) y = np.sin((freq * x + phase)) + shift return Curve(zip(x, y)) keys = itertools.product(phases, freqs, shifts) items = [(key, make_curve(*key)) for key in keys] hmap = HoloMap(items, kdims=['Phase', 'Frequency', 'Shift']) layout = hmap.overlay('Shift').layout(['Frequency', 'Phase']).cols(5) ```

I would have the same question for a “layout” instead of a gridspace. But as far as I understand there is no option in layout to do this automatically and according to the following thread I should manually select a plot and set the legend.

Ticks

Additionally I have a question regarding the xticks and yticks. I would like to show the xticks on the bottom of the gridspace and the yticks on the left size of the gridspace. I don’t immediately see an option in the gridspace to do this. Is there an option to set this?

ahuang11 · March 29, 2024, 6:04pm

I think that issue shows matplotlib backend; bokeh I think you need to use tricks to get a single legend (e.g. hide axes and lines, keep legend).

Gridspace honestly isn’t really well supported from my experience.

I’d personally just lay each plot in a layout and hide axes.

BMM3 · March 30, 2024, 10:58am

Thanks a lot for your reply.
I will work with “layout” and adjust the plots to get what I want.