如何将常规numpy数组转换为记录数组？

Question

我读了一系列数字

np.array(f.read().split(),dtype=np.float64)

然后我使用它将其转换为二维数组np.reshape().

在此之后,如何转换arr为记录数组？我尝试了(类似)以下内容:

filename = 'unstructured-file.txt'
nfields = 3
names = ('r','g','b')
with open(filename,'r') as f:
    arr = np.array(f.read().split(),dtype=np.float64)
    arr = arr.reshape(-1,nfields)
    out = np.array(arr,dtype=zip(names,['float64']*length(names))

但是说 TypeError: expected a readable buffer object

有什么建议？

编辑:我想要做的主要是命名我的列.

代替

out = np.array(arr,dtype=zip(names,['float64']*length(names))

如果我用这个,

out = np.core.records.fromrecords(arr.reshape(-1,nfields),names=','.join(names))

我可以使用out['r']等等,但是out.dtype.names是无.到底是怎么回事？

EDIT2

非结构化文件看起来像

 Some text
 More text
       100  1.000000E-01        46
 -1.891701E+04  1.702921E+02 -2.323660E+04  4.547841E+03 -2.778444E+04
  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00 -2.149862E+04
  1.753467E+02  3.410277E+03 -1.034898E+05  2.778692E+04  0.000000E+00
  0.000000E+00  0.000000E+00  0.000000E+00  1.492281E+04  0.000000E+00
  0.000000E+00  0.000000E+00  9.000000E+01  9.000000E+01  9.000000E+01
  0.000000E+00 -4.774939E-01  0.000000E+00  0.000000E+00  0.000000E+00
 -2.243495E-01  3.513048E-01 -2.678782E-01  3.513048E-01 -7.155493E-01
  5.690034E-01 -2.678782E-01  5.690034E-01 -4.783123E-01  2.461974E+01
  0.000000E+00  0.000000E+00  0.000000E+00  2.461974E+01  0.000000E+00
  0.000000E+00  0.000000E+00  2.461974E+01
       200  2.000000E-01        46
 -1.891815E+04  1.421984E+02 -2.424678E+04  5.199451E+03 -2.944623E+04
  0.000000E+00  0.000000E+00  0.000000E+00  0.000000E+00 -2.174561E+04
  1.274613E+02 -6.004790E+01 -1.139308E+05  2.944807E+04  0.000000E+00
  0.000000E+00  0.000000E+00  0.000000E+00  1.445855E+04  0.000000E+00
  0.000000E+00  0.000000E+00  9.000000E+01  9.000000E+01  9.000000E+01
  0.000000E+00  7.785923E-01  0.000000E+00  0.000000E+00  0.000000E+00
  8.123304E-01  3.023486E-01 -5.891595E-01  3.023486E-01 -8.560144E-02
 -3.830618E-01 -5.891595E-01 -3.830618E-01  1.608437E+00  2.436174E+01
  0.000000E+00  0.000000E+00  0.000000E+00  2.436174E+01  0.000000E+00
  0.000000E+00  0.000000E+00  2.436174E+01

Answer 1

要将普通numpy数组转换为结构化数组,请使用view:

import numpy as np

filename = 'unstructured-file.txt'
nfields = 3
names = ('r','g','b')
with open(filename,'r') as f:
    arr = np.array(f.read().split(),dtype=np.float64)
    arr = arr.reshape(-1,nfields)
    out = arr.view(dtype=zip(names,['float64']*len(names))).copy()