Matplotlib offers these functions:
cla() # Clear axis clf() # Clear figure close() # Close a figure window
When should I use each function and what exactly does it do?
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Answer
They all do different things, since matplotlib uses a hierarchical order in which a figure window contains a figure which may consist of many axes. Additionally, there are functions from the pyplot interface and there are methods on the Figure
class. I will discuss both cases below.
pyplot interface
pyplot
is a module that collects a couple of functions that allow matplotlib to be used in a functional manner. I here assume that pyplot
has been imported as import matplotlib.pyplot as plt
.
In this case, there are three different commands that remove stuff:
See matplotlib.pyplot
Functions:
plt.cla()
clears an axis, i.e. the currently active axis in the current figure. It leaves the other axes untouched.plt.clf()
clears the entire current figure with all its axes, but leaves the window opened, such that it may be reused for other plots.plt.close()
closes a window, which will be the current window, if not specified otherwise.
Which functions suits you best depends thus on your use-case.
The close()
function furthermore allows one to specify which window should be closed. The argument can either be a number or name given to a window when it was created using figure(number_or_name)
or it can be a figure instance fig
obtained, i.e., usingfig = figure()
. If no argument is given to close()
, the currently active window will be closed. Furthermore, there is the syntax close('all')
, which closes all figures.
methods of the Figure class
Additionally, the Figure
class provides methods for clearing figures.
I’ll assume in the following that fig
is an instance of a Figure
:
fig.clf()
clears the entire figure. This call is equivalent to plt.clf()
only if fig
is the current figure.
fig.clear()
is a synonym for fig.clf()
Note that even del fig
will not close the associated figure window. As far as I know the only way to close a figure window is using plt.close(fig)
as described above.