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2 | 2 | Autoscaling |
3 | 3 | =========== |
4 | 4 |
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5 | | -Axis scales define the overall look of a plot, some default options |
6 | | -scale ranges automatically with respect to supplied data - autoscaling. |
7 | | -This tutorial shows concepts of individual autoscaling options and |
8 | | -investigates cornerstone examples regarding the needs for manual adjustments. |
9 | | -The limits on an axis can be set manually (e.g. ``ax.set_xlim(xmin, xmax)``) |
10 | | -or Matplotlib can set them automatically based on the data already on the |
11 | | -axes. There are a number of options to this autoscaling behaviour, |
12 | | -discussed below. |
| 5 | +The limits on an axis can be set manually (e.g. ``ax.set_xlim(xmin, xmax)``) or Matplotlib can set them automatically based on the data already on the axes. There are a number of options to this autoscaling behaviour, discussed below. |
13 | 6 | """ |
14 | 7 |
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15 | 8 | ############################################################################### |
16 | 9 | # We will start with a simple line plot showing that autoscaling |
17 | | -# extends the visible range 5% beyond the real data range (-2π, 2π). |
| 10 | +# extends the axis limits 5% beyond the data limits (-2π, 2π). |
18 | 11 |
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19 | 12 | import numpy as np |
20 | 13 | import matplotlib as mpl |
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30 | 23 | ############################################################################### |
31 | 24 | # Margins |
32 | 25 | # ------- |
33 | | -# The relative measure of the extend is called margin and can be set by |
34 | | -# `~matplotlib.axes.Axes.margins`. |
35 | | -# The default value is (0.05, 0.05): |
| 26 | +# The default margin around the data limits is 5%: |
36 | 27 |
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37 | 28 | ax.margins() |
38 | 29 |
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39 | 30 | ############################################################################### |
40 | | -# The margins can be made larger: |
| 31 | +# The margins can be made larger using `~matplotlib.axes.Axes.margins`: |
41 | 32 |
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42 | 33 | fig, ax = plt.subplots() |
43 | 34 | ax.plot(x, y) |
44 | 35 | ax.margins(0.2, 0.2) |
45 | 36 | fig.show() |
46 | 37 |
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47 | 38 | ############################################################################### |
48 | | -# In general, margins shall be in range (-0.5, ∞), negative margins crop the |
49 | | -# plot showing only a part of the data. Using a single number for margins |
| 39 | +# In general, margins can be in the range (-0.5, ∞), where negative margins set the axes limits to |
| 40 | +# a fraction of the data range, and allow a zoom effect. Using a single number for margins |
50 | 41 | # affects both axes, a single margin can be customized using keyword |
51 | 42 | # arguments ``x`` or ``y``, but positional and keyword interface cannot be |
52 | 43 | # combined |
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57 | 48 | fig.show() |
58 | 49 |
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59 | 50 | ############################################################################### |
60 | | -# There is the last keyword argument for margins call, the ``tight`` option. In |
61 | | -# the case of a simple :func:`~matplotlib.axes.Axes.plot` call, this parameter |
62 | | -# does not change anything, it is passed to the |
63 | | -# :meth:`~matplotlib.axes.Axes.autoscale_view`, which requires more advanced |
64 | | -# discussion. |
65 | 51 | # |
66 | | -# Margins can behave differently for certain plots, this is determined by |
67 | | -# the sticky edges property, which is of interest in the next section. |
68 | 52 | # |
69 | 53 | # Sticky edges |
70 | 54 | # ------------ |
71 | | -# Margin must not be applied for certain :class:`.Artist`, for example, setting |
| 55 | +# Some :class:`.Artist` objects do not allow margins. For example, setting |
72 | 56 | # ``margin=0.2`` on ``plt.imshow`` does not affect the resulting plot. |
73 | 57 | # |
74 | 58 |
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84 | 68 | fig.show() |
85 | 69 |
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86 | 70 | ############################################################################### |
87 | | -# This override of margins is determined by so-called sticky edges. That is a |
88 | | -# property of :class:`.Artist` class, which can suppress adding margins to data |
89 | | -# limits. The effect of sticky edges can be disabled by changing |
90 | | -# :class:`~matplotlib.axes.Axes` property |
91 | | -# `~matplotlib.axes.Axes.use_sticky_edges`. |
92 | | -# |
93 | | -# Settings of sticky edges of individual artists can be investigating by |
94 | | -# accessing them directly, `.Artist.sticky_edges`. Moreover, the values of |
| 71 | +# This override of margins is determined by "sticky edges", a |
| 72 | +# property of :class:`.Artist` class that can suppress adding margins to axis |
| 73 | +# limits. The effect of sticky edges can be disabled on an Axes by changing |
| 74 | +# `~matplotlib.axes.Axes.use_sticky_edges`. |
| 75 | +# Artists have a property `.Artist.sticky_edges`, and the values of |
95 | 76 | # sticky edges can be changed by writing to ``Artist.sticky_edges.x`` or |
96 | | -# ``.Artist.sticky_edges.y`` |
| 77 | +# ``.Artist.sticky_edges.y``. |
97 | 78 | # |
98 | 79 | # The following example shows how overriding works and when it is needed. |
99 | 80 |
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