Matplotlib scatter(): default value for size, marker shape

Question

Is there a way to set default marker size (s) parameter for matplotlib plt.scatter() (or likewise to set the shape of the marker)?

mpl.rcParams.keys() has settings for the line plots, e.g.

import matplotlib as mpl
mpl.rcParams['lines.marker']='D'

... but they do not seem to relate to plt.scatter().

Thanks.

Clarification:

I'd like to use a configuration mechanism like mpl.rcParams(), or some other reasonably civilized method. Locally modifying library code is not it.

On the other hand, if it cannot currently be done and somebody submits a patch to Matplotlib, that would be awesome.

@tcaswell - That would seem like a strange omission, but it's certainly possible. I'll open a feature request issue with mpl unless somebody comes up with an answer in a couple days. — Dmitri
– Dmitri, Commented Oct 4, 2015 at 21:09
There are lots of strange omissions. github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/… <- that is the canonical list of things that can be configured via rcparams. — tacaswell
– tacaswell, Commented Oct 4, 2015 at 21:15
As of a fix pushed in March 2016, the default size of markers for scatter plots can be set - it is based on rcParams['lines.markersize'], see the commit: github.com/matplotlib/matplotlib/commit/…. Since that's the latest commit to that file, most likely there is still no way to set the default marker shape for scatter plots though (the default appears to be hardcoded as 'o'). — Moot
– Moot, Commented Apr 25, 2017 at 19:37

Leb · Accepted Answer · 2015-10-04 18:31:28Z

8

Of course there is, it's all in the pyplot.py

A snippet from their code:

def scatter(x, y, s=20, c=None, marker='o', cmap=None, norm=None, vmin=None,
            vmax=None, alpha=None, linewidths=None, verts=None, edgecolors=None,
            hold=None, data=None, **kwargs):

The size is set to 20 s=20 and the marker shape is a circle marker='o' which agrees with their documentation

answered Oct 4, 2015 at 18:31

Leb

16k11 gold badges58 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Dmitri Over a year ago

... not sure how this helps. My question is about setting default size; not about doing it in a particular invocation of scatter()

Leb Over a year ago

This is not a particular invocation, that is the default size. If you change that s value in there it'll change across all plt.scatter()

Fabian Rost Over a year ago

The question stated "Locally modifying library code is not it" and I guess that's what you suggest, @Leb, right?

Dan · Accepted Answer · 2021-04-22 01:44:40Z

7

In the current release, marker size is defined as:

"The marker size in points**2. Default is rcParams['lines.markersize'] ** 2."

So setting rcParams['lines.markersize'] should change the default marker size for scatterplots too now. See https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.scatter.html

answered Apr 22, 2021 at 1:44

Dan

711 silver badge2 bronze badges

1 Comment

wellplayed Over a year ago

ty! plt.scatter indeed respects changes made to defaults, e.g., plt.rcParams['lines.markersize'] = 1.25. Also, see matplotlib.org/stable/tutorials/introductory/customizing.html for more info :)

Fabian Rost · Accepted Answer · 2016-06-10 13:41:32Z

0

It is not possible in the current release of matplotlib (http://matplotlib.org/users/customizing.html).

However, there is an option to change the default marker in the master branch on GitHub (https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/rcsetup.py#L1112).

answered Jun 10, 2016 at 13:41

Fabian Rost

2,4232 gold badges17 silver badges27 bronze badges

Collectives™ on Stack Overflow

Matplotlib scatter(): default value for size, marker shape

3 Answers 3

3 Comments

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related