[GRASS-user] Question regarding grass.mapcalc

[Kim Besson]

So your suggestion would be
rass.mapcalc("$L=$lmin+
(($lmax-$lmin)/($QCALmax-$QCALmin)) ($raster_file-$QCALmin)", L=tempL,
lmin=lmin, lmax=lmax, QCALmax=QCALmax, QCALmin=QCALmin,
raster_file=raster_file)

and at the end delete L file?
Thanks
Kim

2010/9/24 Glynn Clements <glynn at gclements.plus.com>

>
> Kim Besson wrote:
>
> > I'm doing a Python script to calibrate a raster image. Since I need to do
> 3
> > different calculations I'm using a tempfile (tempL)
> >
> > This is the code:
> >
> >      tempL = grass.read_command("g.tempfile", pid = "1")
> >     grass.mapcalc("$L=$lmin+ (($lmax-$lmin)/($QCALmax-$QCALmin))*
> > ($raster_file-$QCALmin)", L=tempL, lmin=lmin, lmax=lmax, QCALmax=QCALmax,
> > QCALmin=QCALmin, raster_file=raster_file)
> >
> > Where tempL is a temporary, (lmin,lmax) are floats, QCALmax and QCALmin
> are
> > int and raster_file is a raster map used as input.
> >
> > And I get this:
> > syntax error, unexpected '/', expecting NAME or STRING
> > Parse error
> > ERROR: An error occurred while running r.mapcalc
> >
> > What is happening? I believe it has something to do with tempL. Maybe I'm
> > not doing this right. Can anyone help me on this?
>
> g.tempfile returns the full pathname to a temporary file, not a map
> name.
>
> There isn't a module to generate temporary map names. A common
> approach is to use the name of the script followed by ".tmp".
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>
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