np。savetxt似乎不适合n-d数组。

I'm trying to save a 4-D array using numpy.savetxt, and it does not appear to work.

我尝试使用numpy保存一个4-D数组。它看起来并不起作用。

In [13]: mat = np.zeros((3,3,2,2))
In [14]: mat[0][0][0][0] = 1.5e+10
In [15]: mat[0][0][0][1] = 1.6e+10
In [16]: mat[0][0][1][0] = 1.7e+10
In [17]: mat[0][0][1][1] = 1.8e+10
In [18]: np.savetxt("/tmp/save_mat", mat)
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
----> 1 np.savetxt("/tmp/save_mat", mat)

python2.7/site-packages/numpy/lib/npyio.pyc in savetxt(fname, X, fmt, delimiter, newline, header, footer, comments)
 1158                     print(e)
 1159                     raise TypeError("Mismatch between array dtype ('%s') and "
-> 1160                                     "format specifier ('%s')"
 1161                                     % (str(X.dtype), format))
 1162         if len(footer) > 0:

 TypeError: Mismatch between array dtype ('float64') and format specifier ('%.18e %.18e %.18e')

I edited npyio.py and printed out the actual TypeError instead of the re-raised TypeError, and it was

我编辑npyio。py和打印出实际的类型错误，而不是重新生成的类型错误。

float argument required, not numpy.ndarray

It works fine if I use the binary save method

如果我使用二进制保存方法，效果会很好。

In [20]: fd = open("/tmp/save_mat", "w")
In [21]: np.save(fd, mat)
In [22]: fd.close()

And there is a nonzero file created

这里创建了一个非零文件。

$ ls -al /tmp/save_mat
-rw-r--r--  1  368 May 11 07:17 /tmp/save_mat

The numpy documentation does not say anything about the array dimensions, just that it is "array-like".

numpy文档没有提到数组维度，只是说它是“arrayoid”。

http://docs.scipy.org/doc/numpy/reference/generated/numpy.savetxt.html

numpy.savetxt(fname, X, fmt='%.18e', delimiter=' ', newline='\n', header='', footer='', comments='# ')[source]

numpy。savetxt(帧,X,fmt = ' %。18 e,分隔符= ' ',换行符= ' \ n ',头=”,页脚= "评论= ' # ')[源]

Save an array to a text file. Parameters:

将数组保存到文本文件。参数:

fname : filename or file handle If the filename ends in .gz, the file is automatically saved in compressed gzip format. loadtxt understands gzipped files transparently.

fname:文件名或文件句柄，如果文件名以.gz结尾，则该文件将以压缩gzip格式自动保存。loadtxt可以透明地理解压缩文件。

X : array_like Data to be saved to a text file.

X: array_like数据保存到文本文件中。

Is anybody else seeing this? Is it expected behaviour?

还有其他人看到这个吗?这是预期的行为吗?

1 个解决方案

#1

Look again where you changed the error message:

再次查看您更改错误消息的位置:

for row in X:
   try:
       fh.write(asbytes(format % tuple(row) + newline))
   except TypeError:
   ...

Try this with your mat:

用你的垫子试试这个:

print('%.18e %.18e %.18e'%tuple(np.array([1,2,3]))) # working
for row in mat:
    print('%.18e %.18e %.18e'%tuple(row))   # your error

This is straight forward Python string formatting operation. It only works when the number of elements in row (after conversion to a tuple) matches the number of % specifiers in the format. And the elements have to match - in this case numbers that can be displayed with the %e.

这是直接的Python字符串格式化操作。只有当行中的元素数量(转换为tuple)与格式中%说明符的数量匹配时才有效。元素必须匹配——在这个情况下，可以用%e显示的数字。

There's no provision in savetxt to iterate over the higher dimensions of your array. You have to do that kind of iteration yourself.

在savetxt中没有提供对数组的更高维度进行迭代的规定。你必须自己做这种迭代。

Roughly:

约:

f = open('txt.txt', 'w')
for block in Mat:
   for subblock in block:
       np.savetxt(f, block, fmt=...) # write to open file
       f.write('\n') # spacer line
   f.write('\n')  # another spacer
f.close()

A more detailed answer along the same line:

更详细的答案在同一条线上:

How to write a multidimensional array to a text file?

如何将多维数组写入文本文件?

#1