[Numpy-discussion] design issues - octave 'incompatibilities'
python-ml at nn7.de
Sat Jul 23 09:04:16 EDT 2005
I am new to numarray and as I am trying to use it day-by-day
I am now wondering about certain numeric/numarray design issues. Please
forgive me / correct me as I probably misunderstood certain issues.
-- Why did you choose row-major instead of column major format as
practiced by R/octave/matlab... Doesn't that mean performance problems
as fortran/blas is optimized if you work with the transposed version ?
-- why do vectors have no 'orientation', i.e. there are only row but no
column vectors (or why do you treat matrices/vectors differently, i.e.
have vectors at all as a separate type)
array([1, 2, 3])
array([1, 4, 7])
1 2 3
-- How can one obtain submatrices from full matrices:
numarray gives only elements (which is very, very rarely needed and
should IMHO rather be some extra function):
all one can do in numarray currently is as awkward as this:
also mixing slice and variable does not work a[:,i] - hmmhh seems that
is a major issue for me...
-- why don't you allow iterating over the whole matrix via a single
Traceback (most recent call last):
File "<stdin>", line 1, in ?
IndexError: Index out of range
ans = 2
Are there more elegant ways to do this ? Which issues are likely to be
fixed in the future ?
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