[GRASS5] [bug #2061] (grass) r.los needs FP update

[Markus Neteler]

On Fri, Aug 15, 2003 at 12:31:10AM +0100, Glynn Clements wrote:
> 
> Markus Neteler wrote:
> 
> > > > Sounds good - but the segment library (src/libes/segment/) seems
> > > > to be limited to CELL.
> > > 
> > > That contradicts the documentation, which implies that the cells may
> > > have arbitrary size; i.e. a cell is just "len" bytes, where "len" is
> > > given in the call to segment_format(). Cursory examination of the code
> > > supports the documentation.
> > 
> > OK - I tried to update the code and ended up with
> > WARNING: can't put float row into integer map
> 
> That's a libgis issue; you have to create the output map as FP (with
> G_open_fp_cell_new(), G_open_raster_new(..., FCELL_TYPE) etc) if you
> want to put FP rows.

Right, however I was already using
new = G_open_raster_new (out_layer,FCELL_TYPE);

> If you want to write a CELL map, just open the input map as CELL and
> use CELL internally. G_get_raster_row() etc will coerce FCELL and
> DCELL to CELL (via quantisation rules), but G_put_raster_row() etc
> refuse to coerce FCELL or DCELL to CELL (but will do the other
> combinations).

I would like to write FCELL as the resulting vertical angle (in degrees)
may be nice not to see as CELL.
 
> It wouldn't be difficult to make libgis do those coercions, so
> presumably they were omitted deliberately. Probably due to the
> possibility of overflow.
> 
> > that's why I assumed (after a *quick* grep for CELL in segment)
> > that's related to segment.
> 
> No; the segment library doesn't know anything about GRASS data types
> (and doesn't use any GRASS functions except G_malloc and G_warning). 
> The only occurrences of CELL in the segment code are in comments:
> 
> get_row.c:11:/*  int segment_get_row (SEGMENT *SEG, CELL *buf,int row) */
> put_row.c:12:/*	buf is CELL *   WRAT code	*/
> put_row.c:13:/*  int segment_put_row (SEGMENT *SEG, CELL *buf,int row) */
> 
> The "buf" arguments are actually "void *".

This was a stupid 'grep' done by me, sorry.

OK, found the problem (forgot to update also the cell value variables 'old'
and 'new').

Later I'll commit the change to CVS.

Thanks

 Markus