Den 20.02.2012 08:35, skrev Paul Anton Letnes:
In the language wars, I have one question. Why is Fortran not being considered? Fortran already implements many of the features that we want in NumPy:
Yes ... but it does not make Fortran a systems programming language. Making NumPy is different from using it.
- slicing and similar operations, at least some of the fancy indexing kind - element-wise array operations and function calls - array bounds-checking and other debugging aid (with debugging flags)
That is nice for numerical computing, but not really needed to make NumPy.
- arrays that mentally map very well onto numpy arrays. To me, this spells +1 to ease of contribution, over some abstract C/C++ template
Mentally perhaps, but not binary. NumPy needs uniformly strided memory on the binary level. Fortran just gives this at the mental level. E.g. there is nothing that dictates a Fortran pointer has to be a view, the compiler is free to employ copy-in copy-out. In Fortran, a function call can invalidate a pointer. One would therefore have to store the array in an array of integer*1, and use the intrinsic function transfer() to parse the contents into NumPy dtypes.
- in newer standards it has some nontrivial mathematical functions: gamma, bessel, etc. that numpy lacks right now
That belongs to SciPy.
- compilers that are good at optimizing for floating-point performance, because that's what Fortran is all about
Insanely good, but not when we start to do the (binary, not mentally) strided access that NumPy needs. (Not that C compilers would be any better.)
- not Fortran as such, but BLAS and LAPACK are easily accessed by Fortran - possibly other numerical libraries that can be helpful - Fortran has, in its newer standards, thought of C interoperability. We could still keep bits of the code in C (or even C++?) if we'd like to, or perhaps f2py/Cython could do the wrapping.
Not f2py, as it depends on NumPy. - some programmers know Fortran better than C++. Fortran is at least used by many science guys, like me. That is a valid arguments. Fortran is also much easier to read and debug. Sturla