matplotlib.pyplot
¶
Pyplot function overview¶
pyplot |
matplotlib.pyplot is a state-based interface to matplotlib. |
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matplotlib.pyplot.
plotting
()[source]¶ Function Description acorr
Plot the autocorrelation of x. angle_spectrum
Plot the angle spectrum. annotate
Annotate the point xy with text text. 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 some axis properties. axline
Add an infinitely long straight line. 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 2D field of barbs. barh
Make a horizontal bar plot. box
Turn the axes box on or off on the current axes. 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 an Axes
(defaulting to the current axes) from its figure.draw
Redraw the current figure. draw_if_interactive
errorbar
Plot y versus x as lines and/or markers with attached errorbars. eventplot
Plot identical parallel lines at the given positions. figimage
Add a non-resampled image to the figure. figlegend
Place a legend on the figure. fignum_exists
Return whether the figure with the given id exists. figtext
Add text to figure. figure
Create a new figure, or activate an existing 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, creating one if necessary. gcf
Get the current figure. gci
Get the current colorable artist. get
Return the value of an object's property, or print all of them. get_figlabels
Return a list of existing figure labels. get_fignums
Return a list of existing figure numbers. getp
Return the value of an object's property, or print all of them. grid
Configure the grid lines. hexbin
Make a 2D hexagonal binning plot of points x, y. hist
Plot a histogram. hist2d
Make a 2D histogram plot. hlines
Plot horizontal lines at each y from xmin to xmax. imread
Read an image from a file into an array. imsave
Save an array as an image file. imshow
Display data as an image, i.e., on a 2D regular raster. 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 the interactive mode off. ion
Turn the interactive mode on. isinteractive
Return if pyplot is in "interactive mode" or not. legend
Place a legend on the axes. locator_params
Control behavior of major 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 axes. minorticks_on
Display minor ticks on the axes. new_figure_manager
Create a new figure manager instance. pause
Run the GUI event loop for interval seconds. pcolor
Create a pseudocolor plot with a non-regular rectangular grid. pcolormesh
Create a pseudocolor plot with a non-regular rectangular grid. 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. polar
Make a polar plot. psd
Plot the power spectral density. quiver
Plot a 2D field of arrows. quiverkey
Add a key to a quiver plot. rc
Set the current rcParams
.rc_context
Return a context manager for temporarily changing rcParams. rcdefaults
Restore the rcParams
from Matplotlib's internal default style.rgrids
Get or set the radial gridlines on the current polar plot. savefig
Save the current figure. sca
Set the current Axes to ax and the current Figure to the parent of ax. scatter
A scatter plot of y vs. 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, and applies it to the current image if any. setp
Set a property on an artist object. show
Display all open figures. specgram
Plot a spectrogram. spy
Plot the sparsity pattern of a 2D array. stackplot
Draw a stacked area plot. stem
Create a stem plot. step
Make a step plot. streamplot
Draw streamlines of a vector flow. subplot
Add a subplot to the current figure. subplot2grid
Create a subplot at a specific location inside a regular grid. subplot_mosaic
Build a layout of Axes based on ASCII art or nested lists. subplot_tool
Launch a subplot tool window for a figure. subplots
Create a figure and a set of subplots. subplots_adjust
Adjust the subplot layout parameters. suptitle
Add a centered title to the figure. switch_backend
Close all open figures and set the Matplotlib backend. table
Add a table to an Axes
.text
Add text to the axes. thetagrids
Get or set the theta gridlines on the current polar plot. tick_params
Change the appearance of ticks, tick labels, and gridlines. ticklabel_format
Configure the ScalarFormatter
used by default for linear axes.tight_layout
Adjust the padding between and around subplots. title
Set a title for the axes. tricontour
Draw contour lines on an unstructured triangular grid. tricontourf
Draw contour regions 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 and return a second axes that shares the x-axis. twiny
Make and return a second axes that shares the y-axis. uninstall_repl_displayhook
Uninstall the matplotlib display hook. violinplot
Make a violin plot. vlines
Plot vertical lines. xcorr
Plot the cross correlation between x and y. xkcd
Turn on xkcd sketch-style drawing mode. xlabel
Set the label for the x-axis. xlim
Get or set the x limits of the current axes. xscale
Set the x-axis scale. xticks
Get or set the current tick locations and labels of the x-axis. ylabel
Set the label for the y-axis. ylim
Get or set the y-limits of the current axes. yscale
Set the y-axis scale. yticks
Get or set the current tick locations and labels of the y-axis.
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 Choosing Colormaps in Matplotlib tutorial.
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matplotlib.pyplot.
colormaps
()[source]¶ 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 ofgray
.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
- 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, notLinearSegmentedColormap
. 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 cool linearly-decreasing shades of cyan-magenta 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 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) spring linearly-increasing shades of magenta-yellow summer sequential linearly-increasing shades of green-yellow winter linearly-increasing shades of blue-green 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 A set of cyclic color maps:
Colormap Description hsv red-yellow-green-cyan-blue-magenta-red, formed by changing the hue component in the HSV color space twilight perceptually uniform shades of white-blue-black-red-white twilight_shifted perceptually uniform shades of black-blue-white-red-black 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 turbo Spectral map (purple-blue-green-yellow-orange-red) with a bright center and darker endpoints. A smoother alternative to jet. 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 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