python - 值错误 : x and y must have same first dimension

Question

我收到一条错误消息

ValueError: x and y must have same first dimension.

代码如下:

import matplotlib.pyplot as plt
import matplotlib.dates as mdates
import numpy as np

date,bid,ask = np.loadtxt('GBPUSD1d.txt', unpack=True,
               delimiter =',',converters={0:mdates.strpdate2num('%Y%m%d%H%M%S')}) 
avgLine = ((bid+ask)/2)
patternAr = []
performanceAr = []
patForRec = []
eachPattern = []

def percentChange(startPoint, currentPoint):
        return ((float(currentPoint)- startPoint)/abs(startPoint))*100.00

def patternStorage():
        patStartTime = time.time()
        x = (len(avgLine))-30
        y = 11
        while y < x:
                pattern = []
                p1 = percentChange(avgLine[y-10], avgLine[y-9])
                ...
                p10 = percentChange(avgLine[y-10], avgLine[y])

                outcomeRange = avgLine[y+20:y+30]
                currentPoint = avgLine[y]
                try:
                        avgOutcome = reduce(lambda x, y: x + y, outcomeRange) / len(outcomeRange)
                except Exception, e:
                        print str(e)
                        avgOutcome = 0

                futureOutcome = percentChange(currentPoint, avgOutcome)
                pattern.append(p1)
                pattern.append(p2)
                pattern.append(p3)
                pattern.append(p3)
                pattern.append(p4)
                pattern.append(p5)
                pattern.append(p6)
                pattern.append(p7)
                pattern.append(p8)
                pattern.append(p9)
                pattern.append(p10)
                patternAr.append(pattern)
                performanceAr.append(futureOutcome)
                y += 1

        patEndTime = time.time()
        print len (patternAr)
        print len (performanceAr)
        print 'Patten storage took:', patEndTime - patStartTime, 'seconds'

def currentPattern():
    cp1 = percentChange(avgLine[-11], avgLine[-10])
    ...
    cp10 = percentChange(avgLine[-11], avgLine[-1])
    patForRec.append(cp1)
    ...  
    patForRec.append(cp10)
    print patForRec

def patternRecognition():
    for eachPattern in patternAr:
        sim1 = 100.00 - abs(percentChange(eachPattern[0], patForRec[0]))
        ...
        sim10 = 100.00 - abs(percentChange(eachPattern[9], patForRec[9]))
        howSim =((sim1+sim2+sim3+sim4+sim5+sim6+sim7+sim8+sim9+sim10))/float(10)

        if howSim > 70:
            patdex = patternAr.index(eachPattern)
            print 'predicted outcome',performanceAr[patdex]
            xp = [1,2,3,4,5,6,7,8,9,10]
            fig = plt.figure()
            plt.plot(xp, patForRec)
            plt.plot(xp, eachPattern)
            plt.show()

patternStorage()
currentPattern()
patternRecognition()
print (len(patForRec))
print (len(eachPattern))

完整的错误信息

Traceback (most recent call last):
  File "C:\Python27\ANN.py", line 165, in <module>
    patternRecognition()
  File "C:\Python27\ANN.py", line 131, in patternRecognition
    plt.plot(xp, eachPattern)
  File "C:\Python27\lib\site-packages\matplotlib\pyplot.py", line 3093, in plot
    ret = ax.plot(*args, **kwargs)
  File "C:\Python27\lib\site-packages\matplotlib\axes\_axes.py", line 1373, in plot
    for line in self._get_lines(*args, **kwargs):
  File "C:\Python27\lib\site-packages\matplotlib\axes\_base.py", line 303, in _grab_next_args
    for seg in self._plot_args(remaining, kwargs):
  File "C:\Python27\lib\site-packages\matplotlib\axes\_base.py", line 281, in _plot_args
    x, y = self._xy_from_xy(x, y)
  File "C:\Python27\lib\site-packages\matplotlib\axes\_base.py", line 223, in _xy_from_xy
    raise ValueError("x and y must have same first dimension")
ValueError: x and y must have same first dimension

Answer 1

问题是 eachPattern 有 11 个元素，而 xp 有 10 个元素。原因可能在 的第 52 和 53 行您的代码的 >patternStorage 函数，您将 p3 两次添加到您的列表中:

pattern.append(p3)
pattern.append(p3)

如果您去掉其中的一个，图表就可以绘制得很好。虽然它存储在一个循环中多次绘制，但不知道你是否想这样做......

如果你尝试在循环内做更多的事情，那么你必须编写更少的代码，这种你不小心做了两次的问题就会更少发生。