[GRASS5] Re: src/libes/gmath

[Markus Neteler]

On Sat, Sep 01, 2001 at 12:43:22AM +0100, Glynn Clements wrote: 
> Markus Neteler wrote:
> 
> > I am testing on CRAY, but...
> > 
> >         cc -g  -I/home/t3e/fsn/nhdc/nhdcmark/grass/src/include   -c fft.c -o
> > OBJ.alpha-cray-unicosmk2.0.5.X/fft.o
> > CC-11 cc: ERROR File = fft.c, Line = 67
> >   The indicated directive is not a recognized preprocessing directive.
> > 
> >   #warning fft() not implemented; requires FFTW library from www.fftw.org
> >    ^
> > 
> > Total errors detected in fft.c: 1
> > Make: "cc -g  -I/home/t3e/fsn/nhdc/nhdcmark/grass/src/include   -c fft.c -o
> > OBJ.alpha-cray-unicosmk2.0.5.X/fft.o": Error code 1
> > cmd-2436 make: Stop.
> > 
> > Sorry for this, but it needs to be modified again...
> 
> OK. I'll just remove the #warning line; configure should have
> generated a warning if fftw wasn't found, and i.fft, i.shape and
> r.surf.fractal will appear in error.log.
> 
> > BTW: Does it make sense to move the remaining matrix functions from
> > src/libes/gis to gmath?
> 
> Probably. lu.c (G_ludcmp, G_lubksb) and eigen_tools.c (G_tqli,
> G_tred2) could move to gmath.

Glynn,

thanks for your fixes. Concerning jacobi.c: Is the same functionality
eventually already provided in eigen_tools.c (just guessing, I can talk
to a colleague on Monday)?

> The main issue in forming a common vector/matrix library is converting
> existing code to use a common format. So far I've encountered four
> formats:
> 
> 1. "double **a", zero-based: gmath/eigen.c, gis/eigen_tools.c,
> gis/lu.c, i.pca.
> 
> 2. "double **a", arbitrary ranges: r.param.scale
> 
> 3. "double a[MX][MX]", one-based: gmath/jacobi.c, i.cca
> 
> 4. "mat_struct *a": la.c
> 
> The main problem with using a structure is that most of the existing
> code uses "a[i][j]" to access matrices.

Sorry, no idea here (hi developers!). But it should be conform...

Concerning CRAY and directives:

grass-commit wrote:
[...]
Remove #warning from gmath/fft.c
[...]

What about a platform sensitive switch (ifndef __CRAY__) or so to allow
such #warning  for all other platforms? Another #warning also in la.c.
On the other hand "configure" is chatting.

Markus