python matplotlib绘制等高线,plt.contour(),ax3.contour()和plt.contourf(),ax3.contour(), 同名函数
引用文章
https://blog.csdn.net/lanchunhui/article/details/70495353
-
首先这是由不同对象调用的函数,ax3指3D Figure对象即
, plt指 对象, 即matplotlib.pyplot, 是一个模块, plt的函数(方法)就是这个模块的函数(方法). 但它们ax3和plt却具有相同名称的函数(方法), 特别容易混淆, 真令人头疼!!! -
下面直接看官方doc解释:
ax3.contour():
Signature:
ax3.contour(
X,
Y,
Z,
*args,
extend3d=False,
stride=5,
zdir='z',
offset=None,
**kwargs,
)
Docstring:
Create a 3D contour plot.
Parameters
----------
X, Y, Z : array-likes
Input data.
extend3d : bool
Whether to extend contour in 3D; defaults to False.
stride : int
Step size for extending contour.
zdir : {'x', 'y', 'z'}
The direction to use; defaults to 'z'.
offset : scalar
If specified, plot a projection of the contour lines at this
position in a plane normal to zdir
*args, **kwargs
Other arguments are forwarded to `matplotlib.axes.Axes.contour`.
Returns
-------
matplotlib.contour.QuadContourSet
File: c:\users\huawei\appdata\local\programs\python\python36\lib\site-packages\mpl_toolkits\mplot3d\axes3d.py
Type: method
plt.contour():
Signature: plt.contour(*args, data=None, **kwargs)
Docstring:
Plot contours.
Call signature::
contour([X, Y,] Z, [levels], **kwargs)
`.contour` and `.contourf` draw contour lines and filled contours,
respectively. Except as noted, function signatures and return values
are the same for both versions.
Parameters
----------
X, Y : array-like, optional
The coordinates of the values in *Z*.
*X* and *Y* must both be 2-D with the same shape as *Z* (e.g.
created via `numpy.meshgrid`), or they must both be 1-D such
that ``len(X) == M`` is the number of columns in *Z* and
``len(Y) == N`` is the number of rows in *Z*.
If not given, they are assumed to be integer indices, i.e.
``X = range(M)``, ``Y = range(N)``.
Z : array-like(N, M)
The height values over which the contour is drawn.
levels : int or array-like, optional
Determines the number and positions of the contour lines / regions.
If an int *n*, use *n* data intervals; i.e. draw *n+1* contour
lines. The level heights are automatically chosen.
If array-like, draw contour lines at the specified levels.
The values must be in increasing order.
Returns
-------
c : `~.contour.QuadContourSet`
Other Parameters
----------------
corner_mask : bool, optional
Enable/disable corner masking, which only has an effect if *Z* is
a masked array. If ``False``, any quad touching a masked point is
masked out. If ``True``, only the triangular corners of quads
nearest those points are always masked out, other triangular
corners comprising three unmasked points are contoured as usual.
Defaults to :rc:`contour.corner_mask`, which defaults to ``True``.
colors : color string or sequence of colors, optional
The colors of the levels, i.e. the lines for `.contour` and the
areas for `.contourf`.
The sequence is cycled for the levels in ascending order. If the
sequence is shorter than the number of levels, it's repeated.
As a shortcut, single color strings may be used in place of
one-element lists, i.e. ``'red'`` instead of ``['red']`` to color
all levels with the same color. This shortcut does only work for
color strings, not for other ways of specifying colors.
By default (value *None*), the colormap specified by *cmap*
will be used.
alpha : float, optional
The alpha blending value, between 0 (transparent) and 1 (opaque).
cmap : str or `.Colormap`, optional
A `.Colormap` instance or registered colormap name. The colormap
maps the level values to colors.
Defaults to :rc:`image.cmap`.
If given, *colors* take precedence over *cmap*.
norm : `~matplotlib.colors.Normalize`, optional
If a colormap is used, the `.Normalize` instance scales the level
values to the canonical colormap range [0, 1] for mapping to
colors. If not given, the default linear scaling is used.
vmin, vmax : float, optional
If not *None*, either or both of these values will be supplied to
the `.Normalize` instance, overriding the default color scaling
based on *levels*.
origin : {*None*, 'upper', 'lower', 'image'}, optional
Determines the orientation and exact position of *Z* by specifying
the position of ``Z[0, 0]``. This is only relevant, if *X*, *Y*
are not given.
- *None*: ``Z[0, 0]`` is at X=0, Y=0 in the lower left corner.
- 'lower': ``Z[0, 0]`` is at X=0.5, Y=0.5 in the lower left corner.
- 'upper': ``Z[0, 0]`` is at X=N+0.5, Y=0.5 in the upper left
corner.
- 'image': Use the value from :rc:`image.origin`.
extent : (x0, x1, y0, y1), optional
If *origin* is not *None*, then *extent* is interpreted as in
`.imshow`: it gives the outer pixel boundaries. In this case, the
position of Z[0,0] is the center of the pixel, not a corner. If
*origin* is *None*, then (*x0*, *y0*) is the position of Z[0,0],
and (*x1*, *y1*) is the position of Z[-1,-1].
This argument is ignored if *X* and *Y* are specified in the call
to contour.
locator : ticker.Locator subclass, optional
The locator is used to determine the contour levels if they
are not given explicitly via *levels*.
Defaults to `~.ticker.MaxNLocator`.
extend : {'neither', 'both', 'min', 'max'}, optional, default: 'neither'
Determines the ``contourf``-coloring of values that are outside the
*levels* range.
If 'neither', values outside the *levels* range are not colored.
If 'min', 'max' or 'both', color the values below, above or below
and above the *levels* range.
Values below ``min(levels)`` and above ``max(levels)`` are mapped
to the under/over values of the `.Colormap`. Note, that most
colormaps do not have dedicated colors for these by default, so
that the over and under values are the edge values of the colormap.
You may want to set these values explicitly using
`.Colormap.set_under` and `.Colormap.set_over`.
.. note::
An exising `.QuadContourSet` does not get notified if
properties of its colormap are changed. Therefore, an explicit
call `.QuadContourSet.changed()` is needed after modifying the
colormap. The explicit call can be left out, if a colorbar is
assigned to the `.QuadContourSet` because it internally calls
`.QuadContourSet.changed()`.
Example::
x = np.arange(1, 10)
y = x.reshape(-1, 1)
h = x * y
cs = plt.contourf(h, levels=[10, 30, 50],
colors=['#808080', '#A0A0A0', '#C0C0C0'], extend='both')
cs.cmap.set_over('red')
cs.cmap.set_under('blue')
cs.changed()
xunits, yunits : registered units, optional
Override axis units by specifying an instance of a
:class:`matplotlib.units.ConversionInterface`.
antialiased : bool, optional
Enable antialiasing, overriding the defaults. For
filled contours, the default is *True*. For line contours,
it is taken from :rc:`lines.antialiased`.
Nchunk : int >= 0, optional
If 0, no subdivision of the domain. Specify a positive integer to
divide the domain into subdomains of *nchunk* by *nchunk* quads.
Chunking reduces the maximum length of polygons generated by the
contouring algorithm which reduces the rendering workload passed
on to the backend and also requires slightly less RAM. It can
however introduce rendering artifacts at chunk boundaries depending
on the backend, the *antialiased* flag and value of *alpha*.
linewidths : float or sequence of float, optional
*Only applies to* `.contour`.
The line width of the contour lines.
If a number, all levels will be plotted with this linewidth.
If a sequence, the levels in ascending order will be plotted with
the linewidths in the order specified.
Defaults to :rc:`lines.linewidth`.
linestyles : {*None*, 'solid', 'dashed', 'dashdot', 'dotted'}, optional
*Only applies to* `.contour`.
If *linestyles* is *None*, the default is 'solid' unless the lines
are monochrome. In that case, negative contours will take their
linestyle from :rc:`contour.negative_linestyle` setting.
*linestyles* can also be an iterable of the above strings
specifying a set of linestyles to be used. If this
iterable is shorter than the number of contour levels
it will be repeated as necessary.
hatches : List[str], optional
*Only applies to* `.contourf`.
A list of cross hatch patterns to use on the filled areas.
If None, no hatching will be added to the contour.
Hatching is supported in the PostScript, PDF, SVG and Agg
backends only.
Notes
-----
1. `.contourf` differs from the MATLAB version in that it does not draw
the polygon edges. To draw edges, add line contours with calls to
`.contour`.
2. `.contourf` fills intervals that are closed at the top; that is, for
boundaries *z1* and *z2*, the filled region is::
z1 < Z <= z2
except for the lowest interval, which is closed on both sides (i.e.
it includes the lowest value).
File: c:\users\huawei\appdata\local\programs\python\python36\lib\site-packages\matplotlib\pyplot.py
Type: function
ax3.contourf():
Signature: ax3.contourf(X, Y, Z, *args, zdir='z', offset=None, **kwargs)
Docstring:
Create a 3D filled contour plot.
Parameters
----------
X, Y, Z : array-likes
Input data.
zdir : {'x', 'y', 'z'}
The direction to use; defaults to 'z'.
offset : scalar
If specified, plot a projection of the contour lines at this
position in a plane normal to zdir
*args, **kwargs
Other arguments are forwarded to `matplotlib.axes.Axes.contourf`.
Returns
-------
matplotlib.contour.QuadContourSet
Notes
-----
.. versionadded:: 1.1.0
The *zdir* and *offset* parameters.
File: c:\users\huawei\appdata\local\programs\python\python36\lib\site-packages\mpl_toolkits\mplot3d\axes3d.py
Type: method
plt.contourf():
Signature: plt.contourf(*args, data=None, **kwargs)
Docstring:
Plot contours.
Call signature::
contour([X, Y,] Z, [levels], **kwargs)
`.contour` and `.contourf` draw contour lines and filled contours,
respectively. Except as noted, function signatures and return values
are the same for both versions.
Parameters
----------
X, Y : array-like, optional
The coordinates of the values in *Z*.
*X* and *Y* must both be 2-D with the same shape as *Z* (e.g.
created via `numpy.meshgrid`), or they must both be 1-D such
that ``len(X) == M`` is the number of columns in *Z* and
``len(Y) == N`` is the number of rows in *Z*.
If not given, they are assumed to be integer indices, i.e.
``X = range(M)``, ``Y = range(N)``.
Z : array-like(N, M)
The height values over which the contour is drawn.
levels : int or array-like, optional
Determines the number and positions of the contour lines / regions.
If an int *n*, use *n* data intervals; i.e. draw *n+1* contour
lines. The level heights are automatically chosen.
If array-like, draw contour lines at the specified levels.
The values must be in increasing order.
Returns
-------
c : `~.contour.QuadContourSet`
Other Parameters
----------------
corner_mask : bool, optional
Enable/disable corner masking, which only has an effect if *Z* is
a masked array. If ``False``, any quad touching a masked point is
masked out. If ``True``, only the triangular corners of quads
nearest those points are always masked out, other triangular
corners comprising three unmasked points are contoured as usual.
Defaults to :rc:`contour.corner_mask`, which defaults to ``True``.
colors : color string or sequence of colors, optional
The colors of the levels, i.e. the lines for `.contour` and the
areas for `.contourf`.
The sequence is cycled for the levels in ascending order. If the
sequence is shorter than the number of levels, it's repeated.
As a shortcut, single color strings may be used in place of
one-element lists, i.e. ``'red'`` instead of ``['red']`` to color
all levels with the same color. This shortcut does only work for
color strings, not for other ways of specifying colors.
By default (value *None*), the colormap specified by *cmap*
will be used.
alpha : float, optional
The alpha blending value, between 0 (transparent) and 1 (opaque).
cmap : str or `.Colormap`, optional
A `.Colormap` instance or registered colormap name. The colormap
maps the level values to colors.
Defaults to :rc:`image.cmap`.
If given, *colors* take precedence over *cmap*.
norm : `~matplotlib.colors.Normalize`, optional
If a colormap is used, the `.Normalize` instance scales the level
values to the canonical colormap range [0, 1] for mapping to
colors. If not given, the default linear scaling is used.
vmin, vmax : float, optional
If not *None*, either or both of these values will be supplied to
the `.Normalize` instance, overriding the default color scaling
based on *levels*.
origin : {*None*, 'upper', 'lower', 'image'}, optional
Determines the orientation and exact position of *Z* by specifying
the position of ``Z[0, 0]``. This is only relevant, if *X*, *Y*
are not given.
- *None*: ``Z[0, 0]`` is at X=0, Y=0 in the lower left corner.
- 'lower': ``Z[0, 0]`` is at X=0.5, Y=0.5 in the lower left corner.
- 'upper': ``Z[0, 0]`` is at X=N+0.5, Y=0.5 in the upper left
corner.
- 'image': Use the value from :rc:`image.origin`.
extent : (x0, x1, y0, y1), optional
If *origin* is not *None*, then *extent* is interpreted as in
`.imshow`: it gives the outer pixel boundaries. In this case, the
position of Z[0,0] is the center of the pixel, not a corner. If
*origin* is *None*, then (*x0*, *y0*) is the position of Z[0,0],
and (*x1*, *y1*) is the position of Z[-1,-1].
This argument is ignored if *X* and *Y* are specified in the call
to contour.
locator : ticker.Locator subclass, optional
The locator is used to determine the contour levels if they
are not given explicitly via *levels*.
Defaults to `~.ticker.MaxNLocator`.
extend : {'neither', 'both', 'min', 'max'}, optional, default: 'neither'
Determines the ``contourf``-coloring of values that are outside the
*levels* range.
If 'neither', values outside the *levels* range are not colored.
If 'min', 'max' or 'both', color the values below, above or below
and above the *levels* range.
Values below ``min(levels)`` and above ``max(levels)`` are mapped
to the under/over values of the `.Colormap`. Note, that most
colormaps do not have dedicated colors for these by default, so
that the over and under values are the edge values of the colormap.
You may want to set these values explicitly using
`.Colormap.set_under` and `.Colormap.set_over`.
.. note::
An exising `.QuadContourSet` does not get notified if
properties of its colormap are changed. Therefore, an explicit
call `.QuadContourSet.changed()` is needed after modifying the
colormap. The explicit call can be left out, if a colorbar is
assigned to the `.QuadContourSet` because it internally calls
`.QuadContourSet.changed()`.
Example::
x = np.arange(1, 10)
y = x.reshape(-1, 1)
h = x * y
cs = plt.contourf(h, levels=[10, 30, 50],
colors=['#808080', '#A0A0A0', '#C0C0C0'], extend='both')
cs.cmap.set_over('red')
cs.cmap.set_under('blue')
cs.changed()
xunits, yunits : registered units, optional
Override axis units by specifying an instance of a
:class:`matplotlib.units.ConversionInterface`.
antialiased : bool, optional
Enable antialiasing, overriding the defaults. For
filled contours, the default is *True*. For line contours,
it is taken from :rc:`lines.antialiased`.
Nchunk : int >= 0, optional
If 0, no subdivision of the domain. Specify a positive integer to
divide the domain into subdomains of *nchunk* by *nchunk* quads.
Chunking reduces the maximum length of polygons generated by the
contouring algorithm which reduces the rendering workload passed
on to the backend and also requires slightly less RAM. It can
however introduce rendering artifacts at chunk boundaries depending
on the backend, the *antialiased* flag and value of *alpha*.
linewidths : float or sequence of float, optional
*Only applies to* `.contour`.
The line width of the contour lines.
If a number, all levels will be plotted with this linewidth.
If a sequence, the levels in ascending order will be plotted with
the linewidths in the order specified.
Defaults to :rc:`lines.linewidth`.
linestyles : {*None*, 'solid', 'dashed', 'dashdot', 'dotted'}, optional
*Only applies to* `.contour`.
If *linestyles* is *None*, the default is 'solid' unless the lines
are monochrome. In that case, negative contours will take their
linestyle from :rc:`contour.negative_linestyle` setting.
*linestyles* can also be an iterable of the above strings
specifying a set of linestyles to be used. If this
iterable is shorter than the number of contour levels
it will be repeated as necessary.
hatches : List[str], optional
*Only applies to* `.contourf`.
A list of cross hatch patterns to use on the filled areas.
If None, no hatching will be added to the contour.
Hatching is supported in the PostScript, PDF, SVG and Agg
backends only.
Notes
-----
1. `.contourf` differs from the MATLAB version in that it does not draw
the polygon edges. To draw edges, add line contours with calls to
`.contour`.
2. `.contourf` fills intervals that are closed at the top; that is, for
boundaries *z1* and *z2*, the filled region is::
z1 < Z <= z2
except for the lowest interval, which is closed on both sides (i.e.
it includes the lowest value).
File: c:\users\huawei\appdata\local\programs\python\python36\lib\site-packages\matplotlib\pyplot.py
Type: function