"""
Illustrate some of the more advanced things that one can do with
contour labels.

See also contour_demo.py.
"""
import matplotlib
import numpy as np
import matplotlib.cm as cm
import matplotlib.mlab as mlab
import matplotlib.ticker as ticker
import matplotlib.pyplot as plt

matplotlib.rcParams['xtick.direction'] = 'out'
matplotlib.rcParams['ytick.direction'] = 'out'

##################################################
# Define our surface
##################################################
delta = 0.025
x = np.arange(-3.0, 3.0, delta)
y = np.arange(-2.0, 2.0, delta)
X, Y = np.meshgrid(x, y)
Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
# difference of Gaussians
Z = 10.0 * (Z2 - Z1)

##################################################
# Make contour labels using creative float classes
# Follows suggestion of Manuel Metz
##################################################
plt.figure()

# Basic contour plot
CS = plt.contour(X, Y, Z)


# Define a class that forces representation of float to look a certain way
# This remove trailing zero so '1.0' becomes '1'
class nf(float):
    def __repr__(self):
        str = '%.1f' % (self.__float__(),)
        if str[-1] == '0':
            return '%.0f' % self.__float__()
        else:
            return '%.1f' % self.__float__()

# Recast levels to new class
CS.levels = [nf(val) for val in CS.levels]

# Label levels with specially formatted floats
if plt.rcParams["text.usetex"]:
    fmt = r'%r \%%'
else:
    fmt = '%r %%'
plt.clabel(CS, CS.levels, inline=True, fmt=fmt, fontsize=10)

##################################################
# Label contours with arbitrary strings using a
# dictionary
##################################################
plt.figure()

# Basic contour plot
CS = plt.contour(X, Y, Z)

fmt = {}
strs = ['first', 'second', 'third', 'fourth', 'fifth', 'sixth', 'seventh']
for l, s in zip(CS.levels, strs):
    fmt[l] = s

# Label every other level using strings
plt.clabel(CS, CS.levels[::2], inline=True, fmt=fmt, fontsize=10)

# Use a Formatter

plt.figure()

CS = plt.contour(X, Y, 100**Z, locator=plt.LogLocator())
fmt = ticker.LogFormatterMathtext()
fmt.create_dummy_axis()
plt.clabel(CS, CS.levels, fmt=fmt)
plt.title("$100^Z$")

plt.show() 

$ py contour_label_demo.py
contour_label_demo.py:24: MatplotlibDeprecationWarning: The bivariate_normal function
                          was deprecated in Matplotlib 2.2 and will be removed in 3.1.
  Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
contour_label_demo.py:25: MatplotlibDeprecationWarning: The bivariate_normal function
                          was deprecated in Matplotlib 2.2 and will be removed in 3.1.
  Z2 = mlab.bivariate_normal(X, Y, 1.5, 0.5, 1, 1)
Traceback (most recent call last):
  File "contour_label_demo.py", line 57, in 
    plt.clabel(CS, CS.levels, inline=True, fmt=fmt, fontsize=10)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/matplotlib/pyplot.py",
                                                                    line 2496, in clabel
    return gca().clabel(CS=CS, *args, **kwargs)
TypeError: clabel() got multiple values for argument 'CS' 

Traceback (most recent call last):
  File "M:\______\contour_label_demo.py", line 24, in 
    Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
         ^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'matplotlib.mlab' has no attribute 'bivariate_normal' 

Traceback (most recent call last):
  File "E:\______\contour_label_demo.py", line 24, in 
    Z1 = mlab.bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)
         ^^^^^^^^^^^^^^^^^^^^^
AttributeError: module 'matplotlib.mlab' has no attribute 'bivariate_normal' 

"""
==================
Contour Label Demo
==================

Illustrate some of the more advanced things that one can do with
contour labels.

See also the :doc:`contour demo example
</gallery/images_contours_and_fields/contour_demo>`.
"""

import matplotlib.pyplot as plt
import numpy as np

import matplotlib.ticker as ticker

# %%
# Define our surface

delta = 0.025
x = np.arange(-3.0, 3.0, delta)
y = np.arange(-2.0, 2.0, delta)
X, Y = np.meshgrid(x, y)
Z1 = np.exp(-X**2 - Y**2)
Z2 = np.exp(-(X - 1)**2 - (Y - 1)**2)
Z = (Z1 - Z2) * 2

# %%
# Make contour labels with custom level formatters


# This custom formatter removes trailing zeros, e.g. "1.0" becomes "1", and
# then adds a percent sign.
def fmt(x):
    s = f"{x:.1f}"
    if s.endswith("0"):
        s = f"{x:.0f}"
    return rf"{s} \%" if plt.rcParams["text.usetex"] else f"{s} %"


# Basic contour plot
fig, ax = plt.subplots()
CS = ax.contour(X, Y, Z)

ax.clabel(CS, CS.levels, inline=True, fmt=fmt, fontsize=10)

# %%
# Label contours with arbitrary strings using a dictionary

fig1, ax1 = plt.subplots()

# Basic contour plot
CS1 = ax1.contour(X, Y, Z)

fmt = {}
strs = ['first', 'second', 'third', 'fourth', 'fifth', 'sixth', 'seventh']
for l, s in zip(CS1.levels, strs):
    fmt[l] = s

# Label every other level using strings
ax1.clabel(CS1, CS1.levels[::2], inline=True, fmt=fmt, fontsize=10)

# %%
# Use a Formatter

fig2, ax2 = plt.subplots()

CS2 = ax2.contour(X, Y, 100**Z, locator=plt.LogLocator())
fmt = ticker.LogFormatterMathtext()
fmt.create_dummy_axis()
ax2.clabel(CS2, CS2.levels, fmt=fmt)
ax2.set_title("$100^Z$")

plt.show()

# %%
#
# .. admonition:: References
#
#    The use of the following functions, methods, classes and modules is shown
#    in this example:
#
#    - `matplotlib.axes.Axes.contour` / `matplotlib.pyplot.contour`
#    - `matplotlib.axes.Axes.clabel` / `matplotlib.pyplot.clabel`
#    - `matplotlib.ticker.LogFormatterMathtext`
#    - `matplotlib.ticker.TickHelper.create_dummy_axis` 

　Python 3.11.6 (matplotlib 3.7.1) 及び Python 3.12.0 (matplotlib 3.8.1) 共に、正常実行できる。

　

　

　

• 2023/11/23 Ver=1.04 Python 3.12.0 (matplotlib 3.8.1)で確認
• 2023/11/23 Ver=1.04 Python 3.11.6 (matplotlib 3.7.1)で確認
• 2023/04/01 Ver=1.03 Python 3.11.2 で確認
• 2020/10/31 Ver=1.01 Python 3.7.8 で確認
• 2018/11/28 Ver=1.01 初版リリース

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