I would like to know if there is a way to combined several figures created with matplotlib in one unique figure.
Most of the existing topics are related to multiple plots within one figure. But here, I have several functions which all create one elaborated figure (not just a plot, the figure itself is a multiple plot with texts, title, legends,...)
So instead of just doing the layout of those several figures using a software like Word, is there a way to directly combined all my figures in one unique figure under python ?
Thank you in advance !
The concept of figure in matplotlib does not allow to have a figure inside a figure. The figure is the canvas for other artists, like axes. You may of course add as many axes to a figure as you like. So for example instead of one figure with 4 axes and another figure with 6 axes, you can create a figure with 10 axes.
A good choice may be to use the gridspec, as detailed on the respecive matplotlib page.
After additional researches, it seems my problem has no easy solution within Matplotlib itself. Multiple figures layout needs external post-processing of plots.
For those having the same problem, here is an interesting link :
Publication-quality figures with matplotlib and svgutils
Related
I am working on a figure where space is constrained and I want to combine my legend using parentheticals as in this picture.
At the moment I just make some parenthesis in my labels for the plot and then edit the figure in Inkscape later on to add the missing markers, but this makes iterating on the plot more expensive in terms of time before having a usable figure. Is there any way to hack matplotlib into doing something similar without having to go through an external program?
I have three boxplot figures that I am loading using pickle and I would like to join and plot them side-by-side. It seems that the recommendation is to plot one figure to begin with and use matplotlib subplots. However, due to the nature of the data this would be difficult and it is easiest to make three separate figure files first. All three figures have the same y axis limits and the same x ticks.
How can I join them such that they are side-by-side on the same row?
The solution is to create a new figure with the layout you want, then insert the Axes from the existing figures into it. You can get the Axes from an existing figure with only one set of Axes using fig.axes[0], then insert it into a new figure by following this answer.
PS Emersons unite!
I'm not really new to matplotlib and I'm deeply ashamed to admit I have always used it as a tool for getting a solution as quick and easy as possible. So I know how to get basic plots, subplots and stuff and have quite a few code which gets reused from time to time...but I have no "deep(er) knowledge" of matplotlib.
Recently I thought I should change this and work myself through some tutorials. However, I am still confused about matplotlibs plt, fig(ure) and ax(arr). What is really the difference?
In most cases, for some "quick'n'dirty' plotting I see people using just pyplot as plt and directly plot with plt.plot. Since I am having multiple stuff to plot quite often, I frequently use f, axarr = plt.subplots()...but most times you see only code putting data into the axarr and ignoring the figure f.
So, my question is: what is a clean way to work with matplotlib? When to use plt only, what is or what should a figure be used for? Should subplots just containing data? Or is it valid and good practice to everything like styling, clearing a plot, ..., inside of subplots?
I hope this is not to wide-ranging. Basically I am asking for some advice for the true purposes of plt <-> fig <-> ax(arr) (and when/how to use them properly).
Tutorials would also be welcome. The matplotlib documentation is rather confusing to me. When one searches something really specific, like rescaling a legend, different plot markers and colors and so on the official documentation is really precise but rather general information is not that good in my opinion. Too much different examples, no real explanations of the purposes...looks more or less like a big listing of all possible API methods and arguments.
pyplot is the 'scripting' level API in matplotlib (its highest level API to do a lot with matplotlib). It allows you to use matplotlib using a procedural interface in a similar way as you can do it with Matlab. pyplot has a notion of 'current figure' and 'current axes' that all the functions delegate to (#tacaswell dixit). So, when you use the functions available on the module pyplot you are plotting to the 'current figure' and 'current axes'.
If you want 'fine-grain' control of where/what your are plotting then you should use an object oriented API using instances of Figure and Axes.
Functions available in pyplot have an equivalent method in the Axes.
From the repo anatomy of matplotlib:
The Figure is the top-level container in this hierarchy. It is the overall window/page that everything is drawn on. You can have multiple independent figures and Figures can contain multiple Axes.
But...
Most plotting occurs on an Axes. The axes is effectively the area that we plot data on and any ticks/labels/etc associated with it. Usually we'll set up an Axes with a call to subplot (which places Axes on a regular grid), so in most cases, Axes and Subplot are synonymous.
Each Axes has an XAxis and a YAxis. These contain the ticks, tick locations, labels, etc.
If you want to know the anatomy of a plot you can visit this link.
I think that this tutorial explains well the basic notions of the object hierarchy of matplotlib like Figure and Axes, as well as the notion of current figure and current Axes.
If you want a quick answer: There is the Figure object which is the container that wraps multiple Axes(which is different from axis) which also contains smaller objects like legends, line, tick marks ... as shown in this image taken from matplotlib documentation
So when we do
>>> import matplotlib.pyplot as plt
>>> fig, ax = plt.subplots()
>>> type(fig)
<class 'matplotlib.figure.Figure'>
>>> type(ax)
<class 'matplotlib.axes._subplots.AxesSubplot'>
We have created a Figure object and an Axes object that is contained in that figure.
pyplot is matlab like API for those who are familiar with matlab and want to make quick and dirty plots
figure is object-oriented API for those who doesn't care about matlab style plotting
So you can use either one but perhaps not both together.
I'm experimenting with Bokeh server. I have a document with three figures and I'm trying to update two of them depending on the selection I perform on the third. The number of lines to plot in the two figures changes every time.
If I could use multi_line, this would be trivial: I would change the xs and ys in the data_source of the multi_line.
Alas, I need to use multiple scatter plots because multi_line does not support hover and I need it.
So, what I would like to accomplish is to clear the two plots every time I select something in the third, and display the scatter plots corresponding to the new selection.
There are a few possible workarounds, of course (appending scatter points to have a single GlyphRenderer with all scatter plots together, for example, but this would mean using very clunky ways to send the right hover message...). But if it was possible to just clear and update single figures, everything would be cleaner. I couldn't find anything in the docs, however.
I have read the thread you created on the mailing list and this other thread where Bryan says:
Technically, glyph renderers are stored in the .renderers property of
Plots, but I would not recommend rooting around there by hand.
Specifically the "Continuous Updating" notebook I linked earlier has
an example of updating both the data and appearance of an existing
glyph using python and push_notebook. There is not any easy way to remove glyphs at the moment,
other options would be:
recreate a new plot
set the glyph to be invisble
update the glyphs data
So it seems they are the only solutions at the moment
I am writing a bunch of scripts and functions for processing astronomical data. I have a set of galaxies, for which I want to plot some different properties in a 3-panel plot. I have an example of the layout here:
Now, this is not a problem. But sometimes, I want to create this plot just for a single galaxy. In other cases, I want to make a larger plot consisting of subplots that each are made up of the three+pane structure, like this mockup:
For the sake of modularity and reusability of my code, I would like to do something to the effect of just letting my function return a matplotlib.figure.Figure object and then let the caller - function or interactive session - decide whether to show() or savefig the object or embed it in a larger figure. But I cannot seem to find any hints of this in the documentation or elsewhere, it doesn't seem to be something people do that often.
Any suggestions as to what would be the best road to take? I have speculated whether using axes_grid would be the solution, but it doesn't seem quite clean and caller-agnostic to me. Any suggestions?
The best solution is to separate the figure layout logic from the plotting logic. Write your plotting code something like this:
def three_panel_plot(data, ploting_args, ax1, ax2, ax3):
# what you do to plot
So now the code that turns data -> images takes as arguments the data and where it should plot that data too.
If you want to do just one, it's easy, if you want to do a 3x3 grid, you just need to generate the layout and then loop over the axes sets + data.
The way you are suggesting (returning an object out of your plotting routine) would be very hard in matplotlib, the internals are too connected.