[GRASS-user] GRASS Scripting questions

[Glynn Clements]

António Rocha wrote:

> Greetings Achim
> You are absolutely right. I made a mistake copying the expression.
> 
> Here it goes:
> #itinialization of counter1
> r.mapcalc $GIS_OPT_COUNTER1= "float (0)"
> 
> The cycle:
> IFS=,
> for opt in $GIS_OPT_INPUT; do
>    r.mapcalc $GIS_OPT_COUNTER= "$opt+$GIS_OPT_COUNTER"
> done                      

Don't use the same map as both input and output. Instead:

	tmp=tmp.myscript.$$
	for opt in $GIS_OPT_INPUT; do
		r.mapcalc "$tmp = $opt + $GIS_OPT_COUNTER"
		g.rename --o rast=$tmp,$GIS_OPT_COUNTER
	done

Although for this specific task (adding a list of maps), use
"r.series ... method=sum".

-- 
Glynn Clements <glynn at gclements.plus.com>