保存 pdf 时出现 matplotlib 错误
matplotlib error in when saving pdf
我有以下 python 代码：
import numpy as np
import sklearn as sk
import pandas as pd
import scipy as sp
import matplotlib.pyplot as plt
import sys
from sklearn.decomposition import PCA
from sklearn.svm import OneClassSVM
np.random.seed(0)
x1 = np.random.normal((1,1), 0.1, (200, 2))
x2 = np.random.normal((1,0), .1, (200, 2))
x3 = np.random.normal((0,1), .1, (200, 2))
x4 = np.array([[0.5, 0.5],
[0.5, 1],
[1, 0.5]])
X = np.vstack([x1, x2, x3])#, x4])
X = sk.preprocessing.scale(X)
X_new = np.vstack([x1, x2, x3, x4])
X_new = sk.preprocessing.scale(X_new)
n, p = X_new.shape
anomaly_index = np.array(range(n-3, n))
normal_index = np.array(range(n-3))
#plt.scatter(X_new[normal_index,0], X_new[normal_index,1])
#plt.scatter(X_new[anomaly_index,0], X_new[anomaly_index,1], marker='*', c='r')
#plt.show()
gammas = [0.5]#, 0.7, 0.9]
nus = [0.01]#, 0.3, 0.8]
nrow = len(gammas)
ncol = len(nus)
j = 0
for gamma in gammas:
for nu in nus:
j += 1
svm = OneClassSVM(kernel='rbf', degree=2,
gamma=gamma, coef0=0.0,
tol=0.001,
nu=nu, shrinking=True,
cache_size=200,
verbose=False,
max_iter=-1, random_state=None)
svm.fit(X)
anomaly_score = - svm.decision_function(X_new)
vmin = anomaly_score.min()
vmax = anomaly_score.max()
xx1, yy1 = np.meshgrid(np.linspace(X_new[:,0].min()-0.3,
X_new[:,0].max()+0.3, 1000),
np.linspace(X_new[:,1].min()-0.3,
X_new[:,1].max()+0.3, 1000))
Z1 = svm.decision_function(np.c_[xx1.ravel(), yy1.ravel()])
Z1 = Z1.reshape(xx1.shape)
plt.subplot(nrow, ncol, j)
plt.title(r'$\gamma=$' + str(gamma) + r' $\nu=$' + str(nu) + '')
plt.scatter(X_new[normal_index, 0], X_new[normal_index, 1],
c=anomaly_score[normal_index], alpha=2, s=50,
vmin=vmin, vmax=vmax)
plt.scatter(X_new[anomaly_index, 0],
X_new[anomaly_index, 1], marker='*',
c=anomaly_score[anomaly_index], alpha=2, s=90,
vmin=vmin, vmax=vmax)
plt.colorbar()
#cb = plt.colorbar()
#tick_locator = ticker.MaxNLocator(nbins=5)
#cb.locator = tick_locator
#cb.update_ticks()
plt.contourf( xx1, yy1, Z1, cmap=plt.cm.Blues,
levels=np.linspace(Z1.min(), 0.3, 7), alpha=0.1)
plt.xlim(X_new[:,0].min()-0.3, X_new[:, 0].max()+0.3)
plt.ylim(X_new[:,1].min()-0.3, X_new[:, 1].max()+0.3)
plt.xlabel(r'$x_1$', size=20)
plt.ylabel(r'$x_2$', size=20)
plt.locator_params(nbins=4)
plt.tight_layout()
#plt.savefig('one_class_svm_3_clusters_grid.pdf')
plt.show()
这工作正常，但如果我取消注释 plt.savefig，我会收到以下错误：
Process Python[/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py] finished
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> >>> >>> >>> >>>
Process Python[/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py] finished
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> >>> >>> >>> Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/matplotlib/colors.py", line 355, in to_rgba
'number in rbga sequence outside 0-1 range')
ValueError: number in rbga sequence outside 0-1 range
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py", line 98, in <module>
plt.savefig(plot_path + 'one_class_svm_3_clusters_grid.pdf')
File "/usr/local/lib/python3.4/dist-packages/matplotlib/pyplot.py", line 577, in savefig
res = fig.savefig(*args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/figure.py", line 1476, in savefig
self.canvas.print_figure(*args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py", line 161, in print_figure
FigureCanvasAgg.print_figure(self, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 2211, in print_figure
**kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_pdf.py", line 2485, in print_pdf
self.figure.draw(renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/figure.py", line 1085, in draw
func(*args)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/axes/_base.py", line 2110, in draw
a.draw(renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/collections.py", line 772, in draw
Collection.draw(self, renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/collections.py", line 320, in draw
self._offset_position)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_pdf.py", line 1658, in draw_path_collection
antialiaseds, urls, offset_position):
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 488, in _iter_collection
gc0.set_foreground(fg)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 1008, in set_foreground
self._rgb = colors.colorConverter.to_rgba(fg)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/colors.py", line 376, in to_rgba
'to_rgba: Invalid rgba arg "%s"\n%s' % (str(arg), exc))
ValueError: to_rgba: Invalid rgba arg "[ 0. 0. 0. 2.]"
number in rbga sequence outside 0-1 range
>>>
查看错误信息，它告诉你哪里出了问题。回溯的最后一行显示 rgba 颜色的 alpha（第四个值）设置为 2，而它应该介于 0 和 1 之间。
举个小例子，
x1 = np.random.normal((1,1), 0.1, (200, 2))
plt.scatter(x1[:,0], x1[:,1], alpha=2)
plt.show()
会给出同样的错误信息。只需用 0 到 1 之间的数字替换您的 alpha 值，错误就会消失：
x1 = np.random.normal((1,1), 0.1, (200, 2))
plt.scatter(x1[:,0], x1[:,1], alpha=0.5)
plt.show()
在您的代码中，更改以下行中的 alpha 值。在这里，我将它替换为 0.5，但你可以选择你想要的，只要它在 0 和 1 之间。
plt.scatter(X_new[normal_index, 0], X_new[normal_index, 1],
c=anomaly_score[normal_index], alpha=0.5, s=50,
vmin=vmin, vmax=vmax)
plt.scatter(X_new[anomaly_index, 0],
X_new[anomaly_index, 1], marker='*',
c=anomaly_score[anomaly_index], alpha=0.5, s=90,
vmin=vmin, vmax=vmax)
我有以下 python 代码：
import numpy as np
import sklearn as sk
import pandas as pd
import scipy as sp
import matplotlib.pyplot as plt
import sys
from sklearn.decomposition import PCA
from sklearn.svm import OneClassSVM
np.random.seed(0)
x1 = np.random.normal((1,1), 0.1, (200, 2))
x2 = np.random.normal((1,0), .1, (200, 2))
x3 = np.random.normal((0,1), .1, (200, 2))
x4 = np.array([[0.5, 0.5],
[0.5, 1],
[1, 0.5]])
X = np.vstack([x1, x2, x3])#, x4])
X = sk.preprocessing.scale(X)
X_new = np.vstack([x1, x2, x3, x4])
X_new = sk.preprocessing.scale(X_new)
n, p = X_new.shape
anomaly_index = np.array(range(n-3, n))
normal_index = np.array(range(n-3))
#plt.scatter(X_new[normal_index,0], X_new[normal_index,1])
#plt.scatter(X_new[anomaly_index,0], X_new[anomaly_index,1], marker='*', c='r')
#plt.show()
gammas = [0.5]#, 0.7, 0.9]
nus = [0.01]#, 0.3, 0.8]
nrow = len(gammas)
ncol = len(nus)
j = 0
for gamma in gammas:
for nu in nus:
j += 1
svm = OneClassSVM(kernel='rbf', degree=2,
gamma=gamma, coef0=0.0,
tol=0.001,
nu=nu, shrinking=True,
cache_size=200,
verbose=False,
max_iter=-1, random_state=None)
svm.fit(X)
anomaly_score = - svm.decision_function(X_new)
vmin = anomaly_score.min()
vmax = anomaly_score.max()
xx1, yy1 = np.meshgrid(np.linspace(X_new[:,0].min()-0.3,
X_new[:,0].max()+0.3, 1000),
np.linspace(X_new[:,1].min()-0.3,
X_new[:,1].max()+0.3, 1000))
Z1 = svm.decision_function(np.c_[xx1.ravel(), yy1.ravel()])
Z1 = Z1.reshape(xx1.shape)
plt.subplot(nrow, ncol, j)
plt.title(r'$\gamma=$' + str(gamma) + r' $\nu=$' + str(nu) + '')
plt.scatter(X_new[normal_index, 0], X_new[normal_index, 1],
c=anomaly_score[normal_index], alpha=2, s=50,
vmin=vmin, vmax=vmax)
plt.scatter(X_new[anomaly_index, 0],
X_new[anomaly_index, 1], marker='*',
c=anomaly_score[anomaly_index], alpha=2, s=90,
vmin=vmin, vmax=vmax)
plt.colorbar()
#cb = plt.colorbar()
#tick_locator = ticker.MaxNLocator(nbins=5)
#cb.locator = tick_locator
#cb.update_ticks()
plt.contourf( xx1, yy1, Z1, cmap=plt.cm.Blues,
levels=np.linspace(Z1.min(), 0.3, 7), alpha=0.1)
plt.xlim(X_new[:,0].min()-0.3, X_new[:, 0].max()+0.3)
plt.ylim(X_new[:,1].min()-0.3, X_new[:, 1].max()+0.3)
plt.xlabel(r'$x_1$', size=20)
plt.ylabel(r'$x_2$', size=20)
plt.locator_params(nbins=4)
plt.tight_layout()
#plt.savefig('one_class_svm_3_clusters_grid.pdf')
plt.show()
这工作正常，但如果我取消注释 plt.savefig，我会收到以下错误：
Process Python[/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py] finished
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> >>> >>> >>> >>>
Process Python[/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py] finished
Python 3.4.0 (default, Jun 19 2015, 14:20:21)
[GCC 4.8.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> >>> >>> >>> Traceback (most recent call last):
File "/usr/local/lib/python3.4/dist-packages/matplotlib/colors.py", line 355, in to_rgba
'number in rbga sequence outside 0-1 range')
ValueError: number in rbga sequence outside 0-1 range
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/donbeo/Documents/pythoncode/fault_detection/one_class_svm/oc_svm_3_clusters.py", line 98, in <module>
plt.savefig(plot_path + 'one_class_svm_3_clusters_grid.pdf')
File "/usr/local/lib/python3.4/dist-packages/matplotlib/pyplot.py", line 577, in savefig
res = fig.savefig(*args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/figure.py", line 1476, in savefig
self.canvas.print_figure(*args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_qt5agg.py", line 161, in print_figure
FigureCanvasAgg.print_figure(self, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 2211, in print_figure
**kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_pdf.py", line 2485, in print_pdf
self.figure.draw(renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/figure.py", line 1085, in draw
func(*args)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/axes/_base.py", line 2110, in draw
a.draw(renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/collections.py", line 772, in draw
Collection.draw(self, renderer)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/artist.py", line 59, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/collections.py", line 320, in draw
self._offset_position)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backends/backend_pdf.py", line 1658, in draw_path_collection
antialiaseds, urls, offset_position):
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 488, in _iter_collection
gc0.set_foreground(fg)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/backend_bases.py", line 1008, in set_foreground
self._rgb = colors.colorConverter.to_rgba(fg)
File "/usr/local/lib/python3.4/dist-packages/matplotlib/colors.py", line 376, in to_rgba
'to_rgba: Invalid rgba arg "%s"\n%s' % (str(arg), exc))
ValueError: to_rgba: Invalid rgba arg "[ 0. 0. 0. 2.]"
number in rbga sequence outside 0-1 range
>>>
查看错误信息，它告诉你哪里出了问题。回溯的最后一行显示 rgba 颜色的 alpha（第四个值）设置为 2，而它应该介于 0 和 1 之间。
举个小例子，
x1 = np.random.normal((1,1), 0.1, (200, 2))
plt.scatter(x1[:,0], x1[:,1], alpha=2)
plt.show()
会给出同样的错误信息。只需用 0 到 1 之间的数字替换您的 alpha 值，错误就会消失：
x1 = np.random.normal((1,1), 0.1, (200, 2))
plt.scatter(x1[:,0], x1[:,1], alpha=0.5)
plt.show()
在您的代码中，更改以下行中的 alpha 值。在这里，我将它替换为 0.5，但你可以选择你想要的，只要它在 0 和 1 之间。
plt.scatter(X_new[normal_index, 0], X_new[normal_index, 1],
c=anomaly_score[normal_index], alpha=0.5, s=50,
vmin=vmin, vmax=vmax)
plt.scatter(X_new[anomaly_index, 0],
X_new[anomaly_index, 1], marker='*',
c=anomaly_score[anomaly_index], alpha=0.5, s=90,
vmin=vmin, vmax=vmax)