ValueError:使用序列设置数组元素 [英] ValueError: setting an array element with a sequence

问题描述

这个 Python 代码:

import numpy as p

def firstfunction():
    UnFilteredDuringExSummaryOfMeansArray = []
    MeanOutputHeader=['TestID','ConditionName','FilterType','RRMean','HRMean',
                      'dZdtMaxVoltageMean','BZMean','ZXMean','LVETMean','Z0Mean',
                      'StrokeVolumeMean','CardiacOutputMean','VelocityIndexMean']
    dataMatrix = BeatByBeatMatrixOfMatrices[column]
    roughTrimmedMatrix = p.array(dataMatrix[1:,1:17])


    trimmedMatrix = p.array(roughTrimmedMatrix,dtype=p.float64)  #ERROR THROWN HERE


    myMeans = p.mean(trimmedMatrix,axis=0,dtype=p.float64)
    conditionMeansArray = [TestID,testCondition,'UnfilteredBefore',myMeans[3], myMeans[4], 
                           myMeans[6], myMeans[9], myMeans[10], myMeans[11], myMeans[12],
                           myMeans[13], myMeans[14], myMeans[15]]
    UnFilteredDuringExSummaryOfMeansArray.append(conditionMeansArray)
    secondfunction(UnFilteredDuringExSummaryOfMeansArray)
    return

def secondfunction(UnFilteredDuringExSummaryOfMeansArray):
    RRDuringArray = p.array(UnFilteredDuringExSummaryOfMeansArray,dtype=p.float64)[1:,3]
    return

firstfunction()

抛出此错误消息:

File "mypath\mypythonscript.py", line 3484, in secondfunction
RRDuringArray = p.array(UnFilteredDuringExSummaryOfMeansArray,dtype=p.float64)[1:,3]
ValueError: setting an array element with a sequence.

谁能告诉我如何解决上述损坏代码中的问题，使其停止抛出错误消息?

Can anyone show me what to do to fix the problem in the broken code above so that it stops throwing an error message?

我做了一个打印命令来获取矩阵的内容，这是它打印出来的:

I did a print command to get the contents of the matrix, and this is what it printed out:

UnFilteredDuringExSummaryOfMeansArray 是:

UnFilteredDuringExSummaryOfMeansArray is:

[['TestID', 'ConditionName', 'FilterType', 'RRMean', 'HRMean', 'dZdtMaxVoltageMean', 'BZMean', 'ZXMean', 'LVETMean', 'Z0Mean', 'StrokeVolumeMean', 'CardiacOutputMean', 'VelocityIndexMean'],
[u'HF101710', 'PreEx10SecondsBEFORE', 'UnfilteredBefore', 0.90670000000000006, 66.257731979420001, 1.8305673000000002, 0.11750000000000001, 0.15120546389880002, 0.26870546389879996, 27.628261216480002, 86.944190346160013, 5.767261352345999, 0.066259118585869997],
[u'HF101710', '25W10SecondsBEFORE', 'UnfilteredBefore', 0.68478571428571422, 87.727887206978565, 2.2965444125714285, 0.099642857142857144, 0.14952476549885715, 0.24916762264164286, 27.010483303721429, 103.5237336525, 9.0682762747642869, 0.085022572648242867],
[u'HF101710', '50W10SecondsBEFORE', 'UnfilteredBefore', 0.54188235294117659, 110.74841107829413, 2.6719262705882354, 0.077705882352917643, 0.15051306356552943, 0.2282189459185294, 26.768787504858825, 111.22827075238826, 12.329456404418824, 0.099814258468417641],
[u'HF101710', '75W10SecondsBEFORE', 'UnfilteredBefore', 0.4561904761904762, 131.52996981880955, 3.1818159523809522, 0.074714285714290493, 0.13459344175047619, 0.20930772746485715, 26.391156337028569, 123.27387909873812, 16.214243779323812, 0.1205685359981619]]

对我来说看起来像一个 5 行 x 13 列的矩阵，尽管当通过脚本运行不同的数据时，行数是可变的.使用我在此添加的相同数据.

Looks like a 5 row by 13 column matrix to me, though the number of rows is variable when different data are run through the script. With this same data that I am adding in this.

EDIT 2:但是，脚本抛出了错误.所以我不认为你的想法解释了这里发生的问题.不过还是谢谢你.还有其他想法吗?

EDIT 2: However, the script is throwing an error. So I do not think that your idea explains the problem that is happening here. Thank you, though. Any other ideas?

编辑 3:

仅供参考，如果我替换此问题代码行:

FYI, if I replace this problem line of code:

    RRDuringArray = p.array(UnFilteredDuringExSummaryOfMeansArray,dtype=p.float64)[1:,3]

用这个代替:

    RRDuringArray = p.array(UnFilteredDuringExSummaryOfMeansArray)[1:,3]

然后脚本的那部分工作正常而不会抛出错误，但是这行代码更进一步:

Then that section of the script works fine without throwing an error, but then this line of code further down the line:

p.ylim(.5*RRDuringArray.min(),1.5*RRDuringArray.max())

抛出这个错误:

File "mypath\mypythonscript.py", line 3631, in CreateSummaryGraphics
  p.ylim(.5*RRDuringArray.min(),1.5*RRDuringArray.max())
TypeError: cannot perform reduce with flexible type

所以你可以看到我需要指定数据类型才能在 matplotlib 中使用 ylim，但是指定数据类型会抛出引发这篇文章的错误消息.

So you can see that I need to specify the data type in order to be able to use ylim in matplotlib, but yet specifying the data type is throwing the error message that initiated this post.

推荐答案

从您向我们展示的代码中，我们唯一可以看出的是您正试图从一个形状不像多的列表创建一个数组维数组.例如

From the code you showed us, the only thing we can tell is that you are trying to create an array from a list that isn't shaped like a multi-dimensional array. For example

numpy.array([[1,2], [2, 3, 4]])          # wrong!

或

numpy.array([[1,2], [2, [3, 4]]])        # wrong!

将产生此错误消息，因为输入列表的形状不是(广义的)盒子".可以变成多维数组.所以可能 UnFilteredDuringExSummaryOfMeansArray 包含不同长度的序列.

will yield this error message, because the shape of the input list isn't a (generalised) "box" that can be turned into a multidimensional array. So probably UnFilteredDuringExSummaryOfMeansArray contains sequences of different lengths.

此错误消息的另一个可能原因是尝试将字符串用作 float 类型的数组中的元素:

Another possible cause for this error message is trying to use a string as an element in an array of type float:

numpy.array([1.2, "abc"], dtype=float)   # wrong!

根据您的编辑，这就是您正在尝试的内容.如果你真的想要一个包含字符串和浮点数的 NumPy 数组，你可以使用 dtype object，它使数组能够保存任意 Python 对象:

That is what you are trying according to your edit. If you really want to have a NumPy array containing both strings and floats, you could use the dtype object, which enables the array to hold arbitrary Python objects:

numpy.array([1.2, "abc"], dtype=object)

在不知道您的代码应该完成什么的情况下，我无法确定这是否是您想要的.

Without knowing what your code is supposed to accomplish, I can't tell if this is what you want.

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