How to put text inside a box on a plot in matplotlib

6
votes

I'd like to put a text inside a box on a matplotlib plot, but the documentation gives only example on how to put it in upper right corner (and choosing different corner is not exactly straightforward).

1
pythonmatplotlib

1 Answers

7
votes

Here is the code from the example: 

# these are matplotlib.patch.Patch properties
props = dict(boxstyle='round', facecolor='wheat', alpha=0.5)

# place a text box in upper left in axes coords
ax.text(0.05, 0.95, textstr, transform=ax.transAxes, fontsize=14,
    verticalalignment='top', bbox=props)

Matplotlib coordinates

Using transform=ax.transAxes we can put elements inside a plot in using coordinate system in which point (0, 0) is lower left corner, (0, 1) upper left, (1, 1) upper right, and so on.

To be specific: if we put a text box using position (0, 0) a specific point called anchor will be placed in lower left corner. To change anchor you need to add two arguments to the function call: verticalalignment (possible values: center, top, bottom, baseline) and horizontalalignment (possible values: center, right, left).

So to put box in lower left corner, you need to put lower left corner of the box in the lower left corner of the figure: 

# place a text box in lower left in axes coords
ax.text(0.05, 0.05, textstr, transform=ax.transAxes, fontsize=14,
    verticalalignment='bottom', bbox=props)

Anyways here is the link to ipython-notebook with example for all placements.