matplotlib subplots: how to freeze x and y axis?-CodePudding

Good evening

matplotlib changes the scaling of the diagram when drawing with e.g. hist() or plot(), which is usually great.

Is it possible to freeze the x and y axes in a subplot after drawing, so that further drawing commands do not change them anymore? For example:

fig, (plt1, plt2) = plt.subplots(2, 1, figsize=(20, 10))
plt1.hist(…)
plt1.plot(…)

# How can this get done?:
plt1.Freeze X- and Y-Axis

# Those commands no longer changes the x- and y-axis
plt1.plot(…)
plt1.plot(…)

Thanks a lot, kind regards, Thomas

CodePudding user response：

Use plt.xlim and plt.ylim to get the current limits after plotting the initial plots, then use those values to set the limits after plotting the additional plots:

import matplotlib.pyplot as plt

# initial data
x = [1, 2, 3, 4, 5]
y = [2, 4, 8, 16, 32]
plt.plot(x, y)

# Save the current limits here
xlims = plt.xlim()
ylims = plt.ylim()

# additional data (will change the limits)
new_x = [-10, 100]
new_y = [2, 2]
plt.plot(new_x, new_y)

# Then set the old limits as the current limits here
plt.xlim(xlims)
plt.ylim(ylims)

plt.show()

Output figure (note how the x-axis limits are ~ [1, 5] even though the orange line is defined in the range [-10, 100]) :

CodePudding user response：

To freeze x-axis specify the domain on the plot function:

import matplotlib.pyplot as plt

fig, (plt1, plt2) = plt.subplots(2, 1, figsize=(20, 10))

# range(min, max, step)
n = range(0, 10, 1)  # domain [min, max] = [0, 9]

# make sure your functions has equal length
f = [i * 2 for i in n]
g = [i ** 2 for i in n]

# keep x-axis scale the same by specifying x-axis on the plot function.
plt1.plot(n, f) # funtion (f) range depends on it's value [min, max]
plt1.plot(n, g) # funtion (g) range depends on it's value [min, max]

# range of (f) and (g) impacts the scaling of y-axis

See