Matplotlib - functions

LIMITS

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.xlim.html

plt.xlim(xmin, xmax)
plt.xlim((xmin, xmax))
left, right = plt.xlim()   # return the current xlim
plt.xlim(right=3)  # adjust the right leaving left unchanged
plt.xlim(left=1)  # adjust the left leaving right unchanged

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.ylim.html

plt.ylim(ymin, ymax)
plt.ylim((ymin, ymax))
bottom, top = plt.ylim()   # return the current ylim
plt.ylim(top=3)  # adjust the top leaving bottom unchanged
plt.ylim(bottom=1)  # adjust the bottom leaving top unchanged

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.axis.html

plt.axis([xmin, xmax, ymin, ymax])
xmin, xmax, ymin, ymax = plt.axis()   # return the axis limits
plt.axis('on')   # turn on axis lines and labels (same as True)
plt.axis('off')   # turn off axis lines and labels (same as False)
plt.axis('equal')   # set equal scaling by changing axis limits
plt.axis('scaled')   # set equal scaling by changing dimensions of the plot box
plt.axis('square')   # square plot, forcing xmax-xmin == ymax-ymin
plt.axis('tight')   # set limits just large enough to show all data

TICKS

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.xticks.html
# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.yticks.html

# matplotlib.pyplot.xticks(ticks=None, labels=None, **kwargs)
# matplotlib.pyplot.yticks(ticks=None, labels=None, **kwargs)
# Call signatures:
# locs, labels = plt.yticks()            # get locations and labels
# plt.yticks(ticks, [labels], **kwargs)  # set locations and labels

plt.xticks(np.arange(4), ('X1', 'X2', 'X3', 'X4'))
plt.yticks(np.arange(0, 81, 10))
plt.yticks([])   # disable yticks

SCALES

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.xscale.html
# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.yscale.html

# matplotlib.pyplot.xscale(value, **kwargs)
# matplotlib.pyplot.yscale(value, **kwargs)
# value : "linear", "log", "symlog", "logit"

plt.xscale('log')
plt.yscale('linear')

GRID

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.grid.html

# matplotlib.pyplot.grid(b=None, which='major', axis='both', **kwargs)
# b : bool or None
# which : 'major', 'minor', 'both'
# axis : 'both' (default), 'x', 'y'

# Example 1 (x and y are the same).
plt.grid(color='grey', linestyle='-', linewidth=2)

# Example 2 (x different from y).
plt.grid(color='grey', which='major', axis='x', linestyle='-')
plt.grid(color='grey', which='major', axis='y', linestyle=':')

LINES

# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.hlines.html
# https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.vlines.html

# matplotlib.pyplot.hlines(y, xmin, xmax, colors='k', linestyles='solid',
#     label='', *, data=None, **kwargs)
# Plot horizontal lines at each y from xmin to xmax.
# y : float or array-like
# xmin, xmax : float or array-like
# colors : list of colors or color ('colors' or 'color' can be used)

# matplotlib.pyplot.vlines(x, ymin, ymax, colors='k', linestyles='solid',
#     label='', *, data=None, **kwargs)
# Plot vertical lines at each x from ymin to ymax.

plt.hlines([1,2,4,7], 0, 10, colors=['r','g','r','g'], label='red/green')
#plt.hlines([1,2,4,7], [0,1,2,3], [7,8,9,10], color='r', label='red')
plt.vlines([1,2,4,7], 0, 10, colors='b', label='blue')   # the same color

MISC

plt.gray()   # set the colormap to "gray"

# Available colormaps.
cmaps = plt.cm.datad.keys()   # dict_keys(['Blues', 'BrBG', ..., 'tab20c_r'])

img = plt.imread('photo.png')   # PNG files only
# Read an image from a file into an array.
# Returns the image data as numpy.array.
# The returned array has shape
#    - (M, N) for grayscale images.
#    - (M, N, 3) for RGB images.
#    - (M, N, 4) for RGBA images.