healpy.projaxes.GnomonicAxes.contourf¶
-
GnomonicAxes.
contourf
(*args, **kwargs)¶ Plot contours.
contour()
andcontourf()
draw contour lines and filled contours, respectively. Except as noted, function signatures and return values are the same for both versions.contourf()
differs from the MATLAB version in that it does not draw the polygon edges. To draw edges, add line contours with calls tocontour()
.Call signatures:
contour(Z)
make a contour plot of an array Z. The level values are chosen automatically.
contour(X,Y,Z)
X, Y specify the (x, y) coordinates of the surface
contour(Z,N) contour(X,Y,Z,N)
contour N automatically-chosen levels.
contour(Z,V) contour(X,Y,Z,V)
draw contour lines at the values specified in sequence V
contourf(..., V)
fill the
len(V)-1
regions between the values in Vcontour(Z, **kwargs)
Use keyword args to control colors, linewidth, origin, cmap ... see below for more details.
X and Y must both be 2-D with the same shape as Z, or they must both be 1-D such that
len(X)
is the number of columns in Z andlen(Y)
is the number of rows in Z.C = contour(...)
returns aQuadContourSet
object.Optional keyword arguments:
- colors: [ None | string | (mpl_colors) ]
If None, the colormap specified by cmap will be used.
If a string, like ‘r’ or ‘red’, all levels will be plotted in this color.
If a tuple of matplotlib color args (string, float, rgb, etc), different levels will be plotted in different colors in the order specified.
- alpha: float
- The alpha blending value
- cmap: [ None | Colormap ]
- A cm
Colormap
instance or None. If cmap is None and colors is None, a default Colormap is used. - norm: [ None | Normalize ]
- A
matplotlib.colors.Normalize
instance for scaling data values to colors. If norm is None and colors is None, the default linear scaling is used. - vmin, vmax: [ None | scalar ]
- If not None, either or both of these values will be
supplied to the
matplotlib.colors.Normalize
instance, overriding the default color scaling based on levels. - levels: [level0, level1, ..., leveln]
- A list of floating point numbers indicating the level
curves to draw; eg to draw just the zero contour pass
levels=[0]
- origin: [ None | ‘upper’ | ‘lower’ | ‘image’ ]
If None, the first value of Z will correspond to the lower left corner, location (0,0). If ‘image’, the rc value for
image.origin
will be used.This keyword is not active if X and Y are specified in the call to contour.
extent: [ None | (x0,x1,y0,y1) ]
If origin is not None, then extent is interpreted as in
matplotlib.pyplot.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 keyword is not active if X and Y are specified in the call to contour.
- locator: [ None | ticker.Locator subclass ]
- If locator is None, the default
MaxNLocator
is used. The locator is used to determine the contour levels if they are not given explicitly via the V argument. - extend: [ ‘neither’ | ‘both’ | ‘min’ | ‘max’ ]
- Unless this is ‘neither’, contour levels are automatically
added to one or both ends of the range so that all data
are included. These added ranges are then mapped to the
special colormap values which default to the ends of the
colormap range, but can be set via
matplotlib.colors.Colormap.set_under()
andmatplotlib.colors.Colormap.set_over()
methods. - xunits, yunits: [ None | registered units ]
- Override axis units by specifying an instance of a
matplotlib.units.ConversionInterface
. - antialiased: [ True | False ]
- enable antialiasing, overriding the defaults. For filled contours, the default is True. For line contours, it is taken from rcParams[‘lines.antialiased’].
contour-only keyword arguments:
- linewidths: [ None | number | tuple of numbers ]
If linewidths is None, the default width in
lines.linewidth
inmatplotlibrc
is used.If a number, all levels will be plotted with this linewidth.
If a tuple, different levels will be plotted with different linewidths in the order specified
- linestyles: [ None | ‘solid’ | ‘dashed’ | ‘dashdot’ | ‘dotted’ ]
If linestyles is None, the default is ‘solid’ unless the lines are monochrome. In that case, negative contours will take their linestyle from the
matplotlibrc
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.
contourf-only keyword arguments:
- nchunk: [ 0 | integer ]
- If 0, no subdivision of the domain. Specify a positive integer to divide the domain into subdomains of roughly nchunk by nchunk points. This may never actually be advantageous, so this option may be removed. Chunking introduces artifacts at the chunk boundaries unless antialiased is False.
- hatches:
- 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.
Note: contourf fills intervals that are closed at the top; that is, for boundaries z1 and z2, the filled region is:
z1 < z <= z2
There is one exception: if the lowest boundary coincides with the minimum value of the z array, then that minimum value will be included in the lowest interval.
Examples: