On Mon, Jan 5, 2015 at 11:13 AM, Alan G Isaac <alan.is...@gmail.com> wrote:

> On 1/5/2015 10:48 AM, josef.p...@gmail.com wrote:
> > Dtypes are a mess (in terms of code compatibility). Matlab is much
> nicer, it's all just doubles.
>
>
> 1. Thank goodness for dtypes.
> 2. http://www.mathworks.com/help/matlab/numeric-types.html
> 3. After translating Matlab code to much nicer NumPy,
>     I cannot find any way to say MATLAB is "nicer".
>

Maybe it's my selection bias in matlab, I only wrote or read code in matlab
that used exclusively double.

Of course they are a necessary and great feature.

However, life and code would be simpler if we could just do
x = np.asarray(x, float) or even  x = np.array(x, float)
at the beginning of every function, instead of worrying why a user doesn't
have float and trying to accommodate that choice.

https://github.com/statsmodels/statsmodels/search?q=dtype&type=Issues&utf8=%E2%9C%93

AFAIK, matlab and R still have copy on write, so they don't have to worry
about inplace modifications.

5 lines of code to implement an algorithm, and 50 lines of code for input
checking.


My response was to the issue of code as algorithmic documentation:

There are packages or code supplements to books that come with the
disclaimer that the code is written for educational purposes, to help
understand the algorithm, but is not designed for efficiency or performance
or generality.

The more powerful the language and the "fancier" the code, the larger is
the maintenance and wrapping work.

another example:

a dot product of a float/double 2d array is independent of any numpy
version, and it will produce the same result in numpy 19.0 (except for
different machine precision rounding errors)

a dot product of an array (without dtype and shape restriction) might be
anything and change within a few numpy versions.

Josef



>
> Cheers,
> Alan
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