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Multi-dimensionial array support for savetxt / loadtxt (Trac #1888) #2481
Description
Original ticket http://projects.scipy.org/numpy/ticket/1888 on 2011-06-30 by @brickZA, assigned to unknown.
I think it would be feasible to support multi-dimensional saving/loading quite simply by using multiple line-breaks for 'higher-dimensional' linebreaks.
d3D = numpy.array([[[111, 112], [121, 122]],
[[211, 212], [221, 222]]])
could be written to text quite unambigiously as
111 112
121 122
<--- two line breaks indicate break in the 3rd dimension
211 212
221 222
Similarly, 3 line breaks could indicate a break in the 4th dimension.
Another option would be to have the option to write out text in nested-list format. I.e., simply write
[[[111, 112], [121, 122]], [[211, 212], [221, 222]]]
to the file.
Activity
numpy-gitbot commentedon Oct 23, 2012
@dhomeier wrote on 2011-07-04
To some degree this has already been addressed in #1705. I am in favour of adopting the gnuplot convention of double blank lines between blocks, as there seems to be some demand for reading in files of this style. I don't feel quite comfortable with the way proposed in the patch there to return a regular ndarray(N,M) plus an index list to the blocks though.
As a general comment, basic support for such functionality would indeed be relatively easy to implement, but there are a few design decisions involved (like the above, or should we allow to read data blocks of different sizes or only true 3-dimensional arrays, meaning to raise an error if not all of the blocks have equal length...); and it touches a number of features that have just been cleared up in the code - e.g. the ndmin keyword and the behaviour of the unpack option for regular vs. record arrays. Not sure of the latter can be consistently defined for arbitrary dimensions.
numpy-gitbot commentedon Oct 23, 2012
Milestone changed to
NumPy 2.0by @dhomeier on 2011-07-04