Preserve zoom settings in interactive navigation of matplotlib figure

You need to update the image instead of making a new image each time. As an example:

import numpy as npimport matplotlib.pyplot as pltfrom matplotlib.widgets import Buttonclass DummyPlot(object):    def __init__(self):        self.imsize = (10, 10)        self.data = np.random.random(self.imsize)        self.fig, self.ax = plt.subplots()        self.im = self.ax.imshow(self.data)        buttonax = self.fig.add_axes([0.45, 0.9, 0.1, 0.075])        self.button = Button(buttonax, 'Update')        self.button.on_clicked(self.update)    def update(self, event):        self.data += np.random.random(self.imsize) - 0.5        self.im.set_data(self.data)        self.im.set_clim([self.data.min(), self.data.max()])        self.fig.canvas.draw()    def show(self):        plt.show()p = DummyPlot()p.show()

If you want to plot the data for the first time when you hit "update", one work-around is to plot dummy data first and make it invisible.

import numpy as npimport matplotlib.pyplot as pltfrom matplotlib.widgets import Buttonclass DummyPlot(object):    def __init__(self):        self.imsize = (10, 10)        self.data = np.random.random(self.imsize)        self.fig, self.ax = plt.subplots()        dummy_data = np.zeros(self.imsize)        self.im = self.ax.imshow(dummy_data)        self.im.set_visible(False)        buttonax = self.fig.add_axes([0.45, 0.9, 0.1, 0.075])        self.button = Button(buttonax, 'Update')        self.button.on_clicked(self.update)    def update(self, event):        self.im.set_visible(True)        self.data += np.random.random(self.imsize) - 0.5        self.im.set_data(self.data)        self.im.set_clim([self.data.min(), self.data.max()])        self.fig.canvas.draw()    def show(self):        plt.show()p = DummyPlot()p.show()

Alternately, you could just turn auto-scaling off, and create a new image each time. This will be significantly slower, though.

import numpy as npimport matplotlib.pyplot as pltfrom matplotlib.widgets import Buttonclass DummyPlot(object):    def __init__(self):        self.imsize = (10, 10)        self.fig, self.ax = plt.subplots()        self.ax.axis([-0.5, self.imsize[1] - 0.5,                       self.imsize[0] - 0.5, -0.5])        self.ax.set_aspect(1.0)        self.ax.autoscale(False)        buttonax = self.fig.add_axes([0.45, 0.9, 0.1, 0.075])        self.button = Button(buttonax, 'Update')        self.button.on_clicked(self.update)    def update(self, event):        self.ax.imshow(np.random.random(self.imsize))        self.fig.canvas.draw()    def show(self):        plt.show()p = DummyPlot()p.show()