CODEWITHSUNDEEP
zoomingmatplotlib
BobC
BobC

Reputation: 3490

Matplotlib/Pyplot: How to zoom subplots together?

I have plots of 3-axis accelerometer time-series data (t,x,y,z) in separate subplots I'd like to zoom together. That is, when I use the "Zoom to Rectangle" tool on one plot, when I release the mouse all 3 plots zoom together.

Previously, I simply plotted all 3 axes on a single plot using different colors. But this is useful only with small amounts of data: I have over 2 million data points, so the last axis plotted obscures the other two. Hence the need for separate subplots.

I know I can capture matplotlib/pyplot mouse events (http://matplotlib.sourceforge.net/users/event_handling.html), and I know I can catch other events (http://matplotlib.sourceforge.net/api/backend_bases_api.html#matplotlib.backend_bases.ResizeEvent), but I don't know how to tell what zoom has been requested on any one subplot, and how to replicate it on the other two subplots.

I suspect I have the all the pieces, and need only that one last precious clue...

-BobC

Upvotes: 102

Views: 78367

Answers (4)

Sam P
Sam P

Reputation: 721

I call the following function after making plots to get them linked together. It will get all subplots from the current figure, and link their x axes.

import matplotlib.pyplot as plt
def linkx():
  # Get current figure
  axes = plt.gcf().axes 
  parent = axes[0]
  # Loop over other axes and link to first axes
  for i in range(1,len(axes)): 
    axes[i].sharex(parent)

Upvotes: -1

Jeremy McGibbon
Jeremy McGibbon

Reputation: 3775

You can also do this with plt.subplots, if that's your style.

fig, ax = plt.subplots(3, 1, sharex=True, sharey=True)

Upvotes: 78

n1nj4
n1nj4

Reputation: 526

Interactively this works on separate axes

for ax in fig.axes:
    ax.set_xlim(0, 50)
fig.draw()

Upvotes: -2

Ray
Ray

Reputation: 4671

The easiest way to do this is by using the sharex and/or sharey keywords when creating the axes:

from matplotlib import pyplot as plt

ax1 = plt.subplot(2,1,1)
ax1.plot(...)
ax2 = plt.subplot(2,1,2, sharex=ax1)
ax2.plot(...)

Upvotes: 158

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