Re-adjusting (automatically) limits on plot in matplotlib - python

Is there a way to let matplotlib know to recompute the optimal bounds of a plot?
My problem is that, I am manually computing a bunch of boxplots, putting them at various locations in a plot. By the end, some boxplots extend beyond the plot frame. I could hard-code some xlim and ylim's for now, but I want a more general solution.
What I was thinking was a feature where you say "ok plt I am done plotting, now please adjust the bounds so that all my data is nicely within the bounds".
Is this possible?
EDIT:
The answer is yes.
Follow-up question: Can this be done for the ticks as well?

You want to use matplotlib's automatic axis scaling. You can do this with either axes.axis with the "auto" input or axes.set_autoscale_on
ax.axis('auto')
ax.set_autoscale_on()
If you want to auto-scale only the x or y axis, you can use set_autoscaley_on or set_autoscalex_on.

Related

How to adjust subplots borders in matplotlib automatically?

When plotting multiple plots using plt.subplots, most of the time the spacing between subplots is not ideal so the the xtick labels of the top plot would overlap with the title of the bottom plots. There is a way to fix this manually by calling say plt.subplots_adjust(hspace=0.5) and changing the parameters interactively to obtain a decent looking plot. Is there a way to calculate the subplot_adjust parameter automatically? Meaning finding the minimum hspace and wspace so that there is not overlap between texts of the plots.
You can use tight_layout https://matplotlib.org/stable/tutorials/intermediate/tight_layout_guide.html or constrained_layout https://matplotlib.org/stable/tutorials/intermediate/constrainedlayout_guide.html
I'm pretty certain that the closest your going to find to an inbuilt calculation method is:
plt.tight_layout()
or
figure.Figure.tight_layout() #if you are using the object version of the code

How does matplotlib determine its x limits?

I am currently trying to find out on what basis matplotlib sets its automatic plot limit.
The question arose when I plotted some x_values against some y_values.
For the x_values the following holds: min(x_values) = -801.01 and max(x_values) = 798.80. The limits set by matplotlib are (-1000, 800).
As the data is almost symmetrical around 0, therefore I would like it to be plotted symmetrically around 0. Is there anyway I can tell matplotlib to automatically center the plot? Also matplotlib seems to set the "resolution" on it's limits as 200 in this case which seems a bit high to me.
Of course I could set limits manually, but I want to avoid that if possible.
PS: I don't know if it matters but I plot the values somewhere and later add the Line2D object to the figure.

How to make data points in a 3D python scatter plot look like "discs" instead of "spheres"

In a standard 3D python plot, each data point is, by default, represented as a sphere in 3D. For the data I'm plotting, the z-axis is very sensitive, while the x and y axes are very general, so is there a way to make each point on the scatter plot spread out over the x and y direction as it normally would with, for example, s=500, but not spread at all along the z-axis? Ideally this would look like a set of stacked discs, rather than overlapping spheres.
Any ideas? I'm relatively new to python and I don't know if there's a way to make custom data points like this with a scatter plot.
I actually was able to do this using the matplotlib.patches library, creating a patch for every data point, and then making it whatever shape I wanted with the help of mpl_toolkits.mplot3d.art3d.
You might look for something called "jittering". Take a look at
Matplotlib: avoiding overlapping datapoints in a "scatter/dot/beeswarm" plot
It works by adding random noise to your data.
Another way might be to reduce the variance of the data on your z-axis (e.g. applying a log-function) or adjusting the scale. You could do that with ax.set_zscale("log"). It is documented here http://matplotlib.org/mpl_toolkits/mplot3d/api.html#mpl_toolkits.mplot3d.axes3d.Axes3D.set_zscale

Multiple tick locators on single axis of a plot in matplotlib

I've done some searching around, and cannot easily find a solution this problem. Effectively, I want to have multiple tick locators on a single axis such that I can do something like in the plot below.
Note how the x-axis starts off logarithmic, but becomes linear once 500 is reached. I figured one possible solution was to simply divide the data into two portions, plot it on two graphs, each with their own locators, and then put the graphs right next to each other so they're seamless, but that seems very unpythonic. Anyone have a better solution?
I suspect the following URL might be of use:
http://matplotlib.org/examples/axes_grid/parasite_simple2.html (click on the plot to have the python code)
If you need some specialized graphs, it's always a good idea to have a look at the Matplotlib gallery:
http://matplotlib.org/gallery.html
EDIT: It is possible to make custom ticks on the X-axis:
http://matplotlib.org/examples/ticks_and_spines/ticklabels_demo_rotation.html
You may find an implementation of this scale by Jesús Torrado here.

Matplotlib: Avoid congestion in X axis

I'm using this code to plot a cumulative frequency plot:
lot = ocum.plot(x='index', y='cdf', yticks=np.arange(0.0, 1.05, 0.1))
plot.set_xlabel("Data usage")`
plot.set_ylabel("CDF")
fig = plot.get_figure()
fig.savefig("overall.png")
How it appears as follows and is very crowded around the initial part. This is due to my data spread. How can I make it more clear? (uploading to postimg because I don't have enough reputation points)
http://postimg.org/image/ii5z4czld/
I hope that I understood what you want: give more space to the visualization of the "CDF" development for smaller "data usage" values, right? Typically, you would achieve this by changing your X axis scale from linear to logarithmic. Head over to Plot logarithmic axes with matplotlib in python for seeing different ways to achieve that. The simplest might be, in your case, to replace plot() with semilogx().

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