"""

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

Color by y-value

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

Use masked arrays to plot a line with different colors by y-value.

"""

import matplotlib.pyplot as plt

import numpy as np

t = np.arange(0.0, 2.0, 0.01)

s = np.sin(2 * np.pi * t)

upper = 0.77

lower = -0.77

supper = np.ma.masked_where(s < upper, s)

slower = np.ma.masked_where(s > lower, s)

smiddle = np.ma.masked_where((s < lower) | (s > upper), s)

fig, ax = plt.subplots()

ax.plot(t, smiddle, t, slower, t, supper)

plt.show()

# %%

#

# .. admonition:: References

#

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

# in this example:

#

# - `matplotlib.axes.Axes.plot` / `matplotlib.pyplot.plot`

#

# .. tags::

#

# styling: color

# styling: conditional

# plot-type: line

# level: beginner