"""

================================

Scales on 3D (Log, Symlog, etc.)

================================

Demonstrate how to use non-linear scales such as logarithmic scales on 3D axes.

3D axes support the same axis scales as 2D plots: 'linear', 'log', 'symlog',

'logit', 'asinh', and custom 'function' scales. This example shows a mix of

scales: linear on X, log on Y, and symlog on Z.

For a complete list of built-in scales, see `matplotlib.scale`. For an overview

of scale transformations, see :doc:`/gallery/scales/scales`.

"""

import matplotlib.pyplot as plt

import numpy as np

# A sine chirp with increasing frequency and amplitude

x = np.linspace(0, 1, 400) # time

y = 10 ** (2 * x) # frequency, growing exponentially from 1 to 100 Hz

phase = 2 * np.pi * (10 ** (2 * x) - 1) / (2 * np.log(10))

z = np.sin(phase) * x **2 * 10 # amplitude, growing quadratically

fig = plt.figure()

ax = fig.add_subplot(projection='3d')

ax.plot(x, y, z)

ax.set_xlabel('Time (linear)')

ax.set_ylabel('Frequency, Hz (log)')

ax.set_zlabel('Amplitude (symlog)')

ax.set_yscale('log')

ax.set_zscale('symlog')

plt.show()

# %%

#

# .. admonition:: References

#

# The use of the following functions, methods, classes and modules is shown

# in this example:

#

# - `mpl_toolkits.mplot3d.axes3d.Axes3D.set_xscale`

# - `mpl_toolkits.mplot3d.axes3d.Axes3D.set_yscale`

# - `mpl_toolkits.mplot3d.axes3d.Axes3D.set_zscale`

# - `matplotlib.scale`

#

# .. tags::

# plot-type: 3D,

# level: beginner