在纯Python中,您可以很容易地逐列增长矩阵:
data = []
for i in something:
newColumn = getColumnDataAsList(i)
data.append(newColumn)
NumPy的数组没有append函数。hstack
函数在零大小的数组上不起作用,因此以下代码将不起作用:
data = numpy.array([])
for i in something:
newColumn = getColumnDataAsNumpyArray(i)
data = numpy.hstack((data, newColumn)) # ValueError: arrays must have same number of dimensions
因此,我的选择是在适当的条件下删除循环中的初始化:
data = None
for i in something:
newColumn = getColumnDataAsNumpyArray(i)
if data is None:
data = newColumn
else:
data = numpy.hstack((data, newColumn)) # works
..。或者使用Python列表并稍后转换为数组:
data = []
for i in something:
newColumn = getColumnDataAsNumpyArray(i)
data.append(newColumn)
data = numpy.array(data)
这两种变体看起来都有点尴尬。有没有更好的解决方案?
https://stackoverflow.com/questions/1783251
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