Python with matplotlib - reusing drawing functions

Question

I have a follow up question to this question.

Is it possible to streamline the figure generation by having multiple python scripts that work on different parts of the figure?

For example, if I have the following functions:

FunctionA: Draw a histogram of something
FunctionB: Draw a box with a text in it
FunctionC: Draw a plot of something C
FunctionD: Draw a plot of something D

How do I go about reusing the above functions in different scripts? If I wanted, for instance, to create a figure with a histogram with a plot of something C, I would somehow call FunctionA and FunctionC from my script. Or, if I wanted a figure with the two plots, I'd call FunctionC and FunctionD.

I'm not sure if I'm explaining myself clearly, but another way of asking this question is this: how do I pass a figure object to a function and then have the function draw something to the passed figure object and then return it back to the main script to add other things like the title or something?

Answer 1

Here you want to use the Artist objects, and pass them as needed to the functions:

import numpy as np
import matplotlib.pyplot as plt

def myhist(ax, color):
    ax.hist(np.log(np.arange(1, 10, .1)), facecolor=color)

def say_something(ax, words):
    t = ax.text(.2, 20., words)
    make_a_dim_yellow_bbox(t)

def make_a_dim_yellow_bbox(txt):
    txt.set_bbox(dict(facecolor='yellow', alpha=.2))

fig = plt.figure()
ax0 = fig.add_subplot(1,2,1)
ax1 = fig.add_subplot(1,2,2)

myhist(ax0, 'blue')
myhist(ax1, 'green')

say_something(ax0, 'this is the blue plot')
say_something(ax1, 'this is the green plot')

plt.show()

Answer 2

Okey, I've figured out how to do this. It was a lot simpler than what I had imagined. It just required a bit of reading here with the figure and axes classes.

In your main script:

import pylab as plt  
import DrawFns  
fig = plt.figure()  
(do something with fig)  
DrawFns.WriteText(fig, 'Testing')  
plt.show()

In your DrawFns.py:

def WriteText(_fig, _text):  
[indent]_fig.text(0, 0, _text)

And that's it! And I can add more functions in DrawFns.py and call them from any script as long as they are included with import call. :D