|
3 | 3 | Labelling subplots |
4 | 4 | ================== |
5 | 5 |
|
6 | | -Labelling subplots is relatively straightforward, and varies, |
7 | | -so Matplotlibdoes not have a general method for doing this. |
| 6 | +Labelling subplots is relatively straightforward, and varies, so Matplotlib |
| 7 | +does not have a general method for doing this. |
8 | 8 |
|
9 | | -Simplest is putting the label inside the axes. Note, here |
10 | | -we use `.pyplot.subplot_mosaic`, and use the subplot labels |
11 | | -as keys for the subplots, which is a nice convenience. However, |
12 | | -the same method works with `.pyplot.subplots` or keys that are |
13 | | -different than what you want to label the subplot with. |
| 9 | +We showcase two methods to position text at a given physical offset (in |
| 10 | +fontsize units or in points) away from a corner of the Axes: one using |
| 11 | +`~.Axes.annotate`, and one using `.ScaledTranslation`. |
| 12 | +
|
| 13 | +For convenience, this example uses `.pyplot.subplot_mosaic` and subplot |
| 14 | +labels as keys for the subplots. However, the approach also works with |
| 15 | +`.pyplot.subplots` or keys that are different than what you want to label the |
| 16 | +subplot with. |
14 | 17 | """ |
15 | 18 |
|
16 | 19 | importmatplotlib.pyplotasplt |
17 | 20 |
|
18 | | -importmatplotlib.transformsasmtransforms |
| 21 | +frommatplotlib.transformsimportScaledTranslation |
19 | 22 |
|
| 23 | +# %% |
20 | 24 | fig,axs=plt.subplot_mosaic([['a)','c)'], ['b)','c)'], ['d)','d)']], |
21 | 25 | layout='constrained') |
22 | | - |
23 | 26 | forlabel,axinaxs.items(): |
24 | | -# label physical distance in and down: |
25 | | -trans=mtransforms.ScaledTranslation(10/72,-5/72,fig.dpi_scale_trans) |
26 | | -ax.text(0.0,1.0,label,transform=ax.transAxes+trans, |
27 | | -fontsize='medium',verticalalignment='top',fontfamily='serif', |
28 | | -bbox=dict(facecolor='0.7',edgecolor='none',pad=3.0)) |
29 | | - |
30 | | -plt.show() |
| 27 | +# Use Axes.annotate to put the label |
| 28 | +# - at the top left corner (axes fraction (0, 1)), |
| 29 | +# - offset half-a-fontsize right and half-a-fontsize down |
| 30 | +# (offset fontsize (+0.5, -0.5)), |
| 31 | +# i.e. just inside the axes. |
| 32 | +ax.annotate( |
| 33 | +label, |
| 34 | +xy=(0,1),xycoords='axes fraction', |
| 35 | +xytext=(+0.5,-0.5),textcoords='offset fontsize', |
| 36 | +fontsize='medium',verticalalignment='top',fontfamily='serif', |
| 37 | +bbox=dict(facecolor='0.7',edgecolor='none',pad=3.0)) |
31 | 38 |
|
32 | 39 | # %% |
33 | | -# We may prefer the labels outside the axes, but still aligned |
34 | | -# with each other, in which case we use a slightly different transform: |
35 | | - |
36 | 40 | fig,axs=plt.subplot_mosaic([['a)','c)'], ['b)','c)'], ['d)','d)']], |
37 | 41 | layout='constrained') |
38 | | - |
39 | 42 | forlabel,axinaxs.items(): |
40 | | -# label physical distance to the left and up: |
41 | | -trans=mtransforms.ScaledTranslation(-20/72,7/72,fig.dpi_scale_trans) |
42 | | -ax.text(0.0,1.0,label,transform=ax.transAxes+trans, |
43 | | -fontsize='medium',va='bottom',fontfamily='serif') |
44 | | - |
45 | | -plt.show() |
| 43 | +# Use ScaledTranslation to put the label |
| 44 | +# - at the top left corner (axes fraction (0, 1)), |
| 45 | +# - offset 20 pixels left and 7 pixels up (offset points (-20, +7)), |
| 46 | +# i.e. just outside the axes. |
| 47 | +ax.text( |
| 48 | +0.0,1.0,label,transform=( |
| 49 | +ax.transAxes+ScaledTranslation(-20/72,+7/72,fig.dpi_scale_trans)), |
| 50 | +fontsize='medium',va='bottom',fontfamily='serif') |
46 | 51 |
|
47 | 52 | # %% |
48 | 53 | # If we want it aligned with the title, either incorporate in the title or |
49 | 54 | # use the *loc* keyword argument: |
50 | 55 |
|
51 | 56 | fig,axs=plt.subplot_mosaic([['a)','c)'], ['b)','c)'], ['d)','d)']], |
52 | 57 | layout='constrained') |
53 | | - |
54 | 58 | forlabel,axinaxs.items(): |
55 | 59 | ax.set_title('Normal Title',fontstyle='italic') |
56 | 60 | ax.set_title(label,fontfamily='serif',loc='left',fontsize='medium') |
|
67 | 71 | # - `matplotlib.figure.Figure.subplot_mosaic` / |
68 | 72 | # `matplotlib.pyplot.subplot_mosaic` |
69 | 73 | # - `matplotlib.axes.Axes.set_title` |
70 | | -# - `matplotlib.axes.Axes.text` |
71 | | -# - `matplotlib.transforms.ScaledTranslation` |
| 74 | +# - `matplotlib.axes.Axes.annotate` |