AssertionError:不兼容的大小:参数'height'必须是长度2或标量(Matplotlib,Python 2.7,绘制图表)

Question

不幸的是,新的一天带来了Python的新问题:/

我有一个用我用Java编写的其他应用程序生成的文件.这个应用程序生成带有一些数据的文件,它是一种随机的东西,因为我不能说每个文件有多少行.示例文件如下所示:

3   Sat Jan 21 00:00:00 2012
7   Sun Mar 11 00:00:00 2012
5   Fri Jan  1 00:00:00 2010
4   Sat Feb  5 00:00:00 2011
8   Sun Apr 11 00:00:00 2010
4   Wed Aug 24 00:00:00 2011
8   Sat Feb 20 00:00:00 2010
3   Thu Oct 13 00:00:00 2011
9   Fri Dec 17 00:00:00 2010
4   Tue Jul 20 00:00:00 2010
8   Fri Dec  2 00:00:00 2011
6   Mon May 31 00:00:00 2010
5   Mon May 16 00:00:00 2011
8   Mon Apr 30 00:00:00 2012
3   Thu Oct 28 00:00:00 2010
1   Tue Jun 19 00:00:00 2012
7   Wed Sep  8 00:00:00 2010

我想绘制一张使用这些数据的图表.在X轴上我想要格式化日期,并在Y轴上从我文件的第一列开始编号.继承我可爱的python代码:

# -*- coding: utf-8 -*-
#!/usr/bin/env python
import wx
import matplotlib
matplotlib.use("TkAgg")
import matplotlib.pyplot as pl
import datetime

def monthNum(month) :
        if month == "Jan" :
            return 1
        elif month == "Feb" :
            return 2
        elif month == "Mar" :
            return 3
        elif month == "Apr" :
            return 4
        elif month == "May" :
            return 5
        elif month == "Jun" :
            return 6
        elif month == "Jul" :
            return 7
        elif month == "Aug" :
            return 8
        elif month == "Sep" :
            return 9
        elif month == "Oct" :
            return 10
        elif month == "Nov" :
            return 11
        elif month == "Dec" :
            return 12

def convertDate(dateTime) :
        line = dateTime.split(' ')
        date = (str(line[2]) + "-" + str(monthNum(line[1])) + "-" + str(line[4]))
        return date

def readFile(filename) :
        values = []
        dates = []
        try :
                with open(filename, "r") as openedFile:
                        for line in openedFile :
                                line = line.strip()
                                data = line.split("\t")
                                values.append(int(data[0]))
                                newDate = convertDate(data[1])
                                dates.append(datetime.datetime.strptime(newDate, "%d-%m-%Y").date())
        except IOError :
                print("IOERROR")
        except ValueError :
                print("VALUE ERROR")
        if len(values) != 0 and len(dates) != 0 :
                drawChart(values, dates, filename)

def drawChart(values, dates, filename):
        fig = pl.figure(dpi=60,figsize=(18, 10))
        ax = fig.add_subplot(1,1,1)
        fig.subplots_adjust(left=0.1, right=0.95, top=0.95, bottom=0.2)
        ax.bar(range(len(dates)), values, facecolor='#777777', align='center', width=0.5, ecolor='black')
        pl.axis('tight')
        ax.set_xticks(range(len(dates)))
        pl.yticks(values)
        ax.set_xticklabels(dates, rotation = 90)
        pl.savefig(filename + ".png")
        pl.show()
        pl.close()

readFile("file.txt")

一切都很好,如果file.txt有一个单行.当它有更多行时,python代码给我一个错误:

VALUE ERROR
Traceback (most recent call last):
  File "test.py", line 71, in <module>
    readFile("file.txt")
  File "test.py", line 56, in readFile
    drawChart(values, dates, filename)
  File "test.py", line 62, in drawChart
    ax.bar(range(len(dates)), values, facecolor='#777777', align='center', width=0.5, ecolor='black')
  File "/usr/lib/pymodules/python2.7/matplotlib/axes.py", line 4733, in bar
    nbars)
AssertionError: incompatible sizes: argument 'height' must be length 2 or scalar

我真的不知道如何解决它.它很好,如果file.txt有一行,但正如我之前写的:我不能说有多少行file.txt(这取决于我的Java应用程序).

任何人？我在Kubuntu 12.04上使用Python 2.7和Matplotlib.

Answer 1

这是因为日期只有2个值.matplotlib的日期长度和值的长度必须相同才能知道该怎么做.如果值是标量,则所有条形将具有相同的高度