在 Mac 上为 Python 2.7 使用 matplotlib

Posted 2023-03-12

【中文标题】在 Mac 上为 Python 2.7 使用 matplotlib

【英文标题】：using matplotlib on Mac for Python 2.7

【发布时间】：2016-12-27 20:04:01

【问题描述】：

想知道是否有人在 Mac OSX 上遇到过类似问题？如果是这样，你如何解决？谢谢。

这里是文档、代码和错误信息，

http://scikit-learn.org/stable/auto_examples/linear_model/plot_iris_logistic.html

#!/usr/bin/python
# -*- coding: utf-8 -*-

"""
=========================================================
Logistic Regression 3-class Classifier
=========================================================

Show below is a logistic-regression classifiers decision boundaries on the
`iris <http://en.wikipedia.org/wiki/Iris_flower_data_set>`_ dataset. The
datapoints are colored according to their labels.

"""
print(__doc__)


# Code source: Gaël Varoquaux
# Modified for documentation by Jaques Grobler
# License: BSD 3 clause

import numpy as np
import matplotlib.pyplot as plt
from sklearn import linear_model, datasets

# import some data to play with
iris = datasets.load_iris()
X = iris.data[:, :2]  # we only take the first two features.
Y = iris.target

h = .02  # step size in the mesh

logreg = linear_model.LogisticRegression(C=1e5)

# we create an instance of Neighbours Classifier and fit the data.
logreg.fit(X, Y)

# Plot the decision boundary. For that, we will assign a color to each
# point in the mesh [x_min, m_max]x[y_min, y_max].
x_min, x_max = X[:, 0].min() - .5, X[:, 0].max() + .5
y_min, y_max = X[:, 1].min() - .5, X[:, 1].max() + .5
xx, yy = np.meshgrid(np.arange(x_min, x_max, h), np.arange(y_min, y_max, h))
Z = logreg.predict(np.c_[xx.ravel(), yy.ravel()])

# Put the result into a color plot
Z = Z.reshape(xx.shape)
plt.figure(1, figsize=(4, 3))
plt.pcolormesh(xx, yy, Z, cmap=plt.cm.Paired)

# Plot also the training points
plt.scatter(X[:, 0], X[:, 1], c=Y, edgecolors='k', cmap=plt.cm.Paired)
plt.xlabel('Sepal length')
plt.ylabel('Sepal width')

plt.xlim(xx.min(), xx.max())
plt.ylim(yy.min(), yy.max())
plt.xticks(())
plt.yticks(())

plt.show()

---

Traceback (most recent call last):
  File "/Users/foo/personal/law/justech/featureExtraction/testLogisticRegression.py", line 22, in <module>
    import matplotlib.pyplot as plt
  File "/Users/foo/miniconda2/lib/python2.7/site-packages/matplotlib/pyplot.py", line 114, in <module>
    _backend_mod, new_figure_manager, draw_if_interactive, _show = pylab_setup()
  File "/Users/foo/miniconda2/lib/python2.7/site-packages/matplotlib/backends/__init__.py", line 32, in pylab_setup
    globals(),locals(),[backend_name],0)
  File "/Users/foo/miniconda2/lib/python2.7/site-packages/matplotlib/backends/backend_macosx.py", line 24, in <module>
    from matplotlib.backends import _macosx
RuntimeError: Python is not installed as a framework. The Mac OS X backend will not be able to function correctly if Python is not installed as a framework. See the Python documentation for more information on installing Python as a framework on Mac OS X. Please either reinstall Python as a framework, or try one of the other backends. If you are Working with Matplotlib in a virtual enviroment see 'Working with Matplotlib in Virtual environments' in the Matplotlib FAQ

【问题讨论】：

"如果您在虚拟环境中使用 Matplotlib，请参阅 Matplotlib 常见问题中的“在虚拟环境中使用 Matplotlib”" -- 你这样做了吗？

@cricket_007，谢谢并投票。我没有使用 virtualenv，不确定 conda 或 miniconda 在这种情况下是否也是所谓的虚拟环境？谢谢。

顺便说一句，您收到的每个回复都无需投票。您尤其不需要声明您正在这样做。

我没用过Anacoda / miniconda，但如果它被用作Virtualenv我不会感到惊讶

@cricket_007 “没有必要对你收到的每一个回复都投赞成票。你尤其不需要说明你正在这样做。”投票并同意 100%。

【参考方案1】：

您使用的是虚拟环境吗？现在它认为你的 python 不是一个框架。在你的终端运行

which python

并确保它返回

/Library/Frameworks/Python.framework/Versions/2.7/bin/python

您可以随时在 python https://www.python.org/downloads/ 将 python 安装为框架

【讨论】：

感谢格兰特，投票，这里是which python /Users/foo/miniconda2/bin/python 的回报，想知道是否将 Python 作为框架安装有什么关系？我只需要使用 matplotlib 作为库，作为 numpy 等。

感谢格兰特的帮助，将您的回复标记为答案。

如果你想使用框架版本，在终端中运行你的脚本 /Library/Frameworks/Python.framework/Versions/2.7/bin/python /path/to/script/