Question about Using r.mapcalculator in Python console

Question

According to the following conversation: Using r.mapcalculator in Python console?

I tried:

##NoData Background=name
##RASTERLAYER_BAND=raster
##nodatabackground=output raster

import processing

ext = RASTERLAYER_BAND.extent() 
a = str(ext.xMinimum()) 
b = str(ext.xMaximum()) 
c = str(ext.yMinimum()) 
d = str(ext.yMaximum()) 
size = a + ',' + b + ',' + c + ',' + d

nodatabackground=processing.runalg('grass:r.mapcalculator', RASTERLAYER_BAND,None,None,None,None,None,'A/A*A',size,0.0,nodatabackground)

But it doesn't work to me. I get the following message: AttributeError: 'unicode' object has no attribute 'extent'

Any idea to solve it?

Answer 1

You probably need to add something like

raster = processing.getObject(RASTERLAYER_BAND)

and remove

nodatabackground=processing.runalg(...)

---

The following works for me:

##NoData Background=name
##RASTERLAYER_BAND=raster
##nodatabackground=output raster

import processing

raster = processing.getObject(RASTERLAYER_BAND)
ext = raster.extent() 
a = str(ext.xMinimum()) 
b = str(ext.xMaximum()) 
c = str(ext.yMinimum()) 
d = str(ext.yMaximum()) 
size = a + ',' + b + ',' + c + ',' + d

processing.runalg('grass:r.mapcalculator', raster,None,None,None,None,None,'A/A*A',size,0.0,nodatabackground)