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### Related Topics

Below we describe several common approaches to plotting with Matplotlib.

# The Pyplot API¶

The `matplotlib.pyplot` module contains functions that allow you to generate many kinds of plots quickly. For examples that showcase the use of the `matplotlib.pyplot` module, see the Pyplot tutorial or the Pyplot. We also recommend that you look into the object-oriented approach to plotting, described below.

`matplotlib.pyplot.``plotting`()
Function Description
`acorr` Plot the autocorrelation of x.
`angle_spectrum` Plot the angle spectrum.
`annotate` Annotate the point `xy` with text `s`.
`arrow` Add an arrow to the axes.
`autoscale` Autoscale the axis view to the data (toggle).
`axes` Add an axes to the current figure and make it the current axes.
`axhline` Add a horizontal line across the axis.
`axhspan` Add a horizontal span (rectangle) across the axis.
`axis` Convenience method to get or set axis properties.
`axvline` Add a vertical line across the axes.
`axvspan` Add a vertical span (rectangle) across the axes.
`bar` Make a bar plot.
`barbs` Plot a 2-D field of barbs.
`barh` Make a horizontal bar plot.
`box` Turn the axes box on or off.
`boxplot` Make a box and whisker plot.
`broken_barh` Plot a horizontal sequence of rectangles.
`cla` Clear the current axes.
`clabel` Label a contour plot.
`clf` Clear the current figure.
`clim` Set the color limits of the current image.
`close` Close a figure window.
`cohere` Plot the coherence between x and y.
`colorbar` Add a colorbar to a plot.
`contour` Plot contours.
`contourf` Plot contours.
`csd` Plot the cross-spectral density.
`delaxes` Remove the given `Axes` ax from the current figure.
`draw` Redraw the current figure.
`errorbar` Plot y versus x as lines and/or markers with attached errorbars.
`eventplot` Plot identical parallel lines at the given positions.
`figimage` Adds a non-resampled image to the figure.
`figlegend` Place a legend in the figure.
`fignum_exists`
`figtext` Add text to figure.
`figure` Creates a new figure.
`fill` Plot filled polygons.
`fill_between` Fill the area between two horizontal curves.
`fill_betweenx` Fill the area between two vertical curves.
`findobj` Find artist objects.
`gca` Get the current `Axes` instance on the current figure matching the given keyword args, or create one.
`gcf` Get a reference to the current figure.
`gci` Get the current colorable artist.
`get_figlabels` Return a list of existing figure labels.
`get_fignums` Return a list of existing figure numbers.
`grid` Turn the axes grids on or off.
`hexbin` Make a hexagonal binning plot.
`hist` Plot a histogram.
`hist2d` Make a 2D histogram plot.
`hlines` Plot horizontal lines at each y from xmin to xmax.
`hold`
`imread` Read an image from a file into an array.
`imsave` Save an array as in image file.
`imshow` Display an image on the axes.
`install_repl_displayhook` Install a repl display hook so that any stale figure are automatically redrawn when control is returned to the repl.
`ioff` Turn interactive mode off.
`ion` Turn interactive mode on.
`ishold`
`isinteractive` Return status of interactive mode.
`legend` Places a legend on the axes.
`locator_params` Control behavior of tick locators.
`loglog` Make a plot with log scaling on both the x and y axis.
`magnitude_spectrum` Plot the magnitude spectrum.
`margins` Set or retrieve autoscaling margins.
`matshow` Display an array as a matrix in a new figure window.
`minorticks_off` Remove minor ticks from the current plot.
`minorticks_on` Display minor ticks on the current plot.
`over`
`pause` Pause for interval seconds.
`pcolor` Create a pseudocolor plot of a 2-D array.
`pcolormesh` Plot a quadrilateral mesh.
`phase_spectrum` Plot the phase spectrum.
`pie` Plot a pie chart.
`plot` Plot y versus x as lines and/or markers.
`plot_date` Plot data that contains dates.
`plotfile` Plot the data in a file.
`polar` Make a polar plot.
`psd` Plot the power spectral density.
`quiver` Plot a 2-D field of arrows.
`quiverkey` Add a key to a quiver plot.
`rc` Set the current rc params.
`rc_context` Return a context manager for managing rc settings.
`rcdefaults` Restore the rc params from Matplotlib’s internal defaults.
`rgrids` Get or set the radial gridlines on a polar plot.
`savefig` Save the current figure.
`sca` Set the current Axes instance to ax.
`scatter` A scatter plot of y vs x with varying marker size and/or color.
`sci` Set the current image.
`semilogx` Make a plot with log scaling on the x axis.
`semilogy` Make a plot with log scaling on the y axis.
`set_cmap` Set the default colormap.
`setp` Set a property on an artist object.
`show` Display a figure.
`specgram` Plot a spectrogram.
`spectral` Set the colormap to “spectral”.
`spy` Plot the sparsity pattern on a 2-D array.
`stackplot` Draws a stacked area plot.
`stem` Create a stem plot.
`step` Make a step plot.
`streamplot` Draws streamlines of a vector flow.
`subplot` Return a subplot axes at the given grid position.
`subplot2grid` Create an axis at specific location inside a regular grid.
`subplot_tool` Launch a subplot tool window for a figure.
`subplots` Create a figure and a set of subplots This utility wrapper makes it convenient to create common layouts of subplots, including the enclosing figure object, in a single call.
`subplots_adjust` Tune the subplot layout.
`suptitle` Add a centered title to the figure.
`switch_backend` Switch the default backend.
`table` Add a table to the current axes.
`text` Add text to the axes.
`thetagrids` Get or set the theta locations of the gridlines in a polar plot.
`tick_params` Change the appearance of ticks, tick labels, and gridlines.
`ticklabel_format` Change the `ScalarFormatter` used by default for linear axes.
`tight_layout` Automatically adjust subplot parameters to give specified padding.
`title` Set a title of the current axes.
`tricontour` Draw contours on an unstructured triangular grid.
`tricontourf` Draw contours on an unstructured triangular grid.
`tripcolor` Create a pseudocolor plot of an unstructured triangular grid.
`triplot` Draw a unstructured triangular grid as lines and/or markers.
`twinx` Make a second axes that shares the x-axis.
`twiny` Make a second axes that shares the y-axis.
`uninstall_repl_displayhook` Uninstalls the matplotlib display hook.
`violinplot` Make a violin plot.
`vlines` Plot vertical lines.
`xcorr` Plot the cross correlation between x and y.
`xkcd` Turns on xkcd sketch-style drawing mode.
`xlabel` Set the x-axis label of the current axes.
`xlim` Get or set the x limits of the current axes.
`xscale` Set the scaling of the x-axis.
`xticks` Get or set the current tick locations and labels of the x-axis.
`ylabel` Set the y-axis label of the current axes.
`ylim` Get or set the y-limits of the current axes.
`yscale` Set the scaling of the y-axis.
`yticks` Get or set the current tick locations and labels of the y-axis.

# The Object-Oriented API¶

Most of these functions also exist as methods in the `matplotlib.axes.Axes` class. You can use them with the “Object Oriented” approach to Matplotlib.

While it is easy to quickly generate plots with the `matplotlib.pyplot` module, we recommend using the object-oriented approach for more control and customization of your plots. See the methods in the `matplotlib.axes.Axes()` class for many of the same plotting functions. For examples of the OO approach to Matplotlib, see the API Examples.

# Colors in Matplotlib¶

There are many colormaps you can use to map data onto color values. Below we list several ways in which color can be utilized in Matplotlib.

For a more in-depth look at colormaps, see the Colormaps in Matplotlib tutorial.

`matplotlib.pyplot.``colormaps`()

Matplotlib provides a number of colormaps, and others can be added using `register_cmap()`. This function documents the built-in colormaps, and will also return a list of all registered colormaps if called.

You can set the colormap for an image, pcolor, scatter, etc, using a keyword argument:

```imshow(X, cmap=cm.hot)
```

or using the `set_cmap()` function:

```imshow(X)
pyplot.set_cmap('hot')
pyplot.set_cmap('jet')
```

In interactive mode, `set_cmap()` will update the colormap post-hoc, allowing you to see which one works best for your data.

All built-in colormaps can be reversed by appending `_r`: For instance, `gray_r` is the reverse of `gray`.

There are several common color schemes used in visualization:

Sequential schemes
for unipolar data that progresses from low to high
Diverging schemes
for bipolar data that emphasizes positive or negative deviations from a central value
Cyclic schemes
meant for plotting values that wrap around at the endpoints, such as phase angle, wind direction, or time of day
Qualitative schemes
for nominal data that has no inherent ordering, where color is used only to distinguish categories

Matplotlib ships with 4 perceptually uniform color maps which are the recommended color maps for sequential data:

Colormap Description
inferno perceptually uniform shades of black-red-yellow
magma perceptually uniform shades of black-red-white
plasma perceptually uniform shades of blue-red-yellow
viridis perceptually uniform shades of blue-green-yellow

The following colormaps are based on the ColorBrewer color specifications and designs developed by Cynthia Brewer:

ColorBrewer Diverging (luminance is highest at the midpoint, and decreases towards differently-colored endpoints):

Colormap Description
BrBG brown, white, blue-green
PiYG pink, white, yellow-green
PRGn purple, white, green
PuOr orange, white, purple
RdBu red, white, blue
RdGy red, white, gray
RdYlBu red, yellow, blue
RdYlGn red, yellow, green
Spectral red, orange, yellow, green, blue

ColorBrewer Sequential (luminance decreases monotonically):

Colormap Description
Blues white to dark blue
BuGn white, light blue, dark green
BuPu white, light blue, dark purple
GnBu white, light green, dark blue
Greens white to dark green
Greys white to black (not linear)
Oranges white, orange, dark brown
OrRd white, orange, dark red
PuBu white, light purple, dark blue
PuBuGn white, light purple, dark green
PuRd white, light purple, dark red
Purples white to dark purple
RdPu white, pink, dark purple
Reds white to dark red
YlGn light yellow, dark green
YlGnBu light yellow, light green, dark blue
YlOrBr light yellow, orange, dark brown
YlOrRd light yellow, orange, dark red

ColorBrewer Qualitative:

(For plotting nominal data, `ListedColormap` is used, not `LinearSegmentedColormap`. Different sets of colors are recommended for different numbers of categories.)

• Accent
• Dark2
• Paired
• Pastel1
• Pastel2
• Set1
• Set2
• Set3

A set of colormaps derived from those of the same name provided with Matlab are also included:

Colormap Description
autumn sequential linearly-increasing shades of red-orange-yellow
bone sequential increasing black-white color map with a tinge of blue, to emulate X-ray film
copper sequential increasing shades of black-copper
flag repetitive red-white-blue-black pattern (not cyclic at endpoints)
gray sequential linearly-increasing black-to-white grayscale
hot sequential black-red-yellow-white, to emulate blackbody radiation from an object at increasing temperatures
hsv cyclic red-yellow-green-cyan-blue-magenta-red, formed by changing the hue component in the HSV color space
jet a spectral map with dark endpoints, blue-cyan-yellow-red; based on a fluid-jet simulation by NCSA [1]
pink sequential increasing pastel black-pink-white, meant for sepia tone colorization of photographs
prism repetitive red-yellow-green-blue-purple-…-green pattern (not cyclic at endpoints)
summer sequential linearly-increasing shades of green-yellow

A set of palettes from the Yorick scientific visualisation package, an evolution of the GIST package, both by David H. Munro are included:

Colormap Description
gist_earth mapmaker’s colors from dark blue deep ocean to green lowlands to brown highlands to white mountains
gist_heat sequential increasing black-red-orange-white, to emulate blackbody radiation from an iron bar as it grows hotter
gist_ncar pseudo-spectral black-blue-green-yellow-red-purple-white colormap from National Center for Atmospheric Research [2]
gist_rainbow runs through the colors in spectral order from red to violet at full saturation (like hsv but not cyclic)
gist_stern “Stern special” color table from Interactive Data Language software

Other miscellaneous schemes:

Colormap Description
afmhot sequential black-orange-yellow-white blackbody spectrum, commonly used in atomic force microscopy
brg blue-red-green
bwr diverging blue-white-red
coolwarm diverging blue-gray-red, meant to avoid issues with 3D shading, color blindness, and ordering of colors [3]
CMRmap “Default colormaps on color images often reproduce to confusing grayscale images. The proposed colormap maintains an aesthetically pleasing color image that automatically reproduces to a monotonic grayscale with discrete, quantifiable saturation levels.” [4]
cubehelix Unlike most other color schemes cubehelix was designed by D.A. Green to be monotonically increasing in terms of perceived brightness. Also, when printed on a black and white postscript printer, the scheme results in a greyscale with monotonically increasing brightness. This color scheme is named cubehelix because the r,g,b values produced can be visualised as a squashed helix around the diagonal in the r,g,b color cube.
gnuplot gnuplot’s traditional pm3d scheme (black-blue-red-yellow)
gnuplot2 sequential color printable as gray (black-blue-violet-yellow-white)
ocean green-blue-white
rainbow spectral purple-blue-green-yellow-orange-red colormap with diverging luminance
seismic diverging blue-white-red
nipy_spectral black-purple-blue-green-yellow-red-white spectrum, originally from the Neuroimaging in Python project
terrain mapmaker’s colors, blue-green-yellow-brown-white, originally from IGOR Pro

The following colormaps are redundant and may be removed in future versions. It’s recommended to use the names in the descriptions instead, which produce identical output:

Colormap Description
gist_gray identical to gray
gist_yarg identical to gray_r
binary identical to gray_r
spectral identical to nipy_spectral [5]

Footnotes

 [1] Rainbow colormaps, `jet` in particular, are considered a poor choice for scientific visualization by many researchers: Rainbow Color Map (Still) Considered Harmful
 [2] Resembles “BkBlAqGrYeOrReViWh200” from NCAR Command Language. See Color Table Gallery
 [3] See Diverging Color Maps for Scientific Visualization by Kenneth Moreland.
 [4] See A Color Map for Effective Black-and-White Rendering of Color-Scale Images by Carey Rappaport
 [5] Changed to distinguish from ColorBrewer’s Spectral map. `spectral()` still works, but `set_cmap('nipy_spectral')` is recommended for clarity.