我有代码来遍历目录中的每个文件并绘制它遇到的每个csv文件。每个CSV都有一个表单
的标题`Timestamp, P1rms (A), P2rms (A), P3rms (A), P4rms (A), P5rms (A), Vrms (V), P1 theta, P2 theta, P3 theta, P4 theta, P5 theta`.
Mon Sep 30 00:00:00 2013, 128, 128, 180, 177, 192, 43, 7, 7, 8, 8, 48
Mon Sep 30 00:00:01 2013, 127, 127, 182, 178, 193, 43, 8, 8, 8, 8, 49
# ect....
我正在开发一个fft可视化选项，当我移动数据集时，我遇到了溢出错误。这是我的确切问题：
当我运行我的代码时：
#!/usr/bin/env python
from pandas import *
import matplotlib.pyplot as plt
import os
import sys
import platform
import numpy.fft as np
# name of plots folder
plotfold='plots'
# System specific info
if platform.system()=='Darwin':comsep="/"
else: comsep="\\"
# How many columns should I plot?
numcol=6
if len(sys.argv)<2:
print 'usage: ./canaryCrawler.py [-c] or [-f] rootdir'
quit()
if len(sys.argv)>2:
ylim=1500
root = sys.argv[2]
else:
ylim=1200
root = sys.argv[1]
for subdir, dirs, files in os.walk(root):
# plot each file
for file in files:
if str(file)[-4:]=='.csv':
print 'plotting '+str(file)+'...'
# load csv as data frame
df=pandas.io.parsers.read_csv(subdir+comsep+file)
for i in range(0,len(df.Timestamp)):
df.Timestamp[i] = datetime.strptime(df.Timestamp[i], '%a %b %d %H:%M:%S %Y')
# We only want the first 6 collumns
df = df.ix[:,0:numcol]
if len(sys.argv)>=2:
if sys.argv[1]=='-c' or sys.argv[1]=='-f':
plotfold='plots_Specialty'
df2 = df
df=pandas.DataFrame(df2.Timestamp)
df['Residence']=df2['P1rms (A)']+df2['P2rms (A)']
df['Specialty']=df2['P3rms (A)']+df2['P4rms (A)']
if sys.argv[1]=='-f':
df2['Residence']=np.fft(df['Residence'])
df2['Specialty']=np.fft(df['Specialty'])
df=df2
print 'Fourier Transformation Complete'
plotfold='plots_Specialty_fft'
# set up plot
plt.figure()
df.plot(df.Timestamp,alpha=0.6,linewidth=2.3) # add transparency to see overlapping colors
plt.tight_layout(pad=1.08)
plt.legend(loc='best') # add legend in non-intrusive location
plt.legend(loc=5,prop={'size':14}) #
plt.ylabel('Current')
plt.xlabel('Time')
plt.gcf().autofmt_xdate()
plt.gcf().set_size_inches(12.7,9.2)
plt.gca().set_ylim([0,ylim])
stamp = df.Timestamp[0]
day = datetime.strftime(stamp,'%a')
DOM=datetime.strftime(stamp,'%d')
month = datetime.strftime(stamp,'%b')
year = datetime.strftime(stamp,'%Y')
plt.title(subdir+' '+day+' '+month+' '+DOM+' '+year)
# keep plot
# check for existing plots folder,
# create one if it doesn't exist
if plotfold not in os.listdir(subdir):
print '** adding plots directory to ',subdir
os.mkdir(subdir+comsep+plotfold)
# save in plots directory
spsubs = str(subdir).split(comsep)
filnam=''
for piece in range(len(spsubs)-4,len(spsubs)-1):
filnam+='_'+spsubs[piece]
filnam+='_'+str(file)[:-4]
saveto=subdir+comsep+plotfold+comsep+filnam
print '**** saving plot to ',saveto
plt.savefig(saveto)
plt.close()
我收到此错误：
kilojoules$ ./canaryCrawler.py -f 35ca7/
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/pandas-0.14.0-py2.7-macosx-10.9-x86_64.egg/pandas/io/excel.py:626: UserWarning: Installed openpyxl is not supported at this time. Use >=1.6.1 and <2.0.0.
.format(openpyxl_compat.start_ver, openpyxl_compat.stop_ver))
plotting 2014Aug04.csv...
Fourier Transformation Complete
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy-1.8.1-py2.7-macosx-10.9-x86_64.egg/numpy/core/numeric.py:460: ComplexWarning: Casting complex values to real discards the imaginary part
return array(a, dtype, copy=False, order=order)
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/tight_layout.py:225: UserWarning: tight_layout : falling back to Agg renderer
warnings.warn("tight_layout : falling back to Agg renderer")
**** saving plot to 35ca7/2014/Aug/plots_Specialty_fft/_Aug_35ca7_2014_2014Aug04
plotting 2014Aug05.csv...
Fourier Transformation Complete
**** saving plot to 35ca7/2014/Aug/plots_Specialty_fft/_Aug_35ca7_2014_2014Aug05
plotting 2014Aug07.csv...
Fourier Transformation Complete
**** saving plot to 35ca7/2014/Aug/plots_Specialty_fft/_Aug_35ca7_2014_2014Aug07
Traceback (most recent call last):
File "./canaryCrawler.py", line 97, in <module>
plt.savefig(saveto)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/pyplot.py", line 561, in savefig
return fig.savefig(*args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 1421, in savefig
self.canvas.print_figure(*args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backend_bases.py", line 2220, in print_figure
**kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 505, in print_png
FigureCanvasAgg.draw(self)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 451, in draw
self.figure.draw(self.renderer)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/figure.py", line 1034, in draw
func(*args)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/axes.py", line 2086, in draw
a.draw(renderer)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/lines.py", line 562, in draw
drawFunc(renderer, gc, tpath, affine.frozen())
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/lines.py", line 938, in _draw_lines
self._lineFunc(renderer, gc, path, trans)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/lines.py", line 978, in _draw_solid
renderer.draw_path(gc, path, trans)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/matplotlib/backends/backend_agg.py", line 145, in draw_path
self._renderer.draw_path(gc, path, transform, rgbFace)
OverflowError: Allocated too many blocks
我在agg.path.chunksize中将matplotlibrc参数指定为o agg.path.chunksize : 10000000。我运行-f fft选项时只会出现此错误。如何防止此错误？
答案 0 :(得分：1)
不确定但请尝试pdf，svg后端
#!/usr/bin/env python
from pandas import *
import matplotlib.pyplot as plt # Insert just before import matplotlib as mpl
mpl.use('pdf') # Insert just before import matplotlib as mpl
import matplotlib as mpl
# ['pdf', 'pgf', 'Qt4Agg', 'GTK', 'GTKAgg', 'ps', 'agg',
# 'cairo', 'MacOSX', 'GTKCairo', 'WXAgg', 'template', 'TkAgg',
# 'GTK3Cairo', 'GTK3Agg', 'svg', 'WebAgg', 'CocoaAgg', 'emf', 'gdk', 'WX']
# (...)
plt.savefig('svg.pdf') # Consider file extension (!)