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Oh, now I understand Victor, it makes r.mapcalc very difficult to use.

So, Grid Calculator has all the functions of r.mapcalc (or most of them)? Is there any place where we can see the list of functions? In this case, it should be preferable to adopt Grid Calculator as the main Sextante raster calculator.

Victor,

I think I've the answer for my question. The best source of information about Grid Calculator should be your great "A Gentle Introduction to SAGA GIS" - Chapter 7.5
http://downloads.sourceforge.net/saga-gis/SagaManual.pdf

- Addition (+)
- Subtraction ( - )
- Multiplication (*)
- Division (/)
- Power (^)
- ln(x): returns natural logarithm of x. (but ln(e) will not return 1 !!!)
- sin(x): returns the sine of x. x must be in radians
- cos(x): returns the cosine of x. x must be in radians
- cos(x): returns the tangente of x. x must be in radians
- asin(x): returns the arcsine of x, in radians
- acos(x): returns the arccosine of x, in radians
- atan(x): returns the arctangent of x, in radians
- atan2(x,y): returns the arctangent y/x, in radians
- abs(x): return the absolute value of x. abs( - 5 )=5
- int(x): returns the integer part of x. int(5.4)=5
- mod(x,y): returns the modulus of x/y. mod(7,4)=3
- gt(x,y): true if x is greater than y
- lt(x,y): true if x is lower than y
- eq(x,y): true if x equals y. When using this function SAGA evaluates it in a per–cell basis. Therefore, eq(a,b) will not return 1 if grid a equals grid b. It will return 1 for those cells that have the same value in both grids, and zero otherwise.
- ifelse(condition, x, y) returns x if condition evaluates to true (condition=1) or y if it
evaluates to false

It's a fairly comprehensive list, and from those functions that I regularly use, I'm just noting the lack of a round funtion:
- round(x): round x to nearest integer

Is there any other way to achieve the round function? We can always use: int((x+0.5))

Thanks!

See also Feature #6372 - r.mapcalculator

Hi Giovanni,
I hope someone can find a solution, because this module is important and the limitation of r.mapcalculator to 6 input raster, makes its use very limited.

I stress the importance of having GRASS mapcalc, as it is very flexible, and may be the only (easiest) way of doing proximity calculations.

Adding r.mapcalc becomes now paramount because in GRASS 7 there is no more r.mapcalculator

there is hope see

https://trac.osgeo.org/grass/ticket/2592

Giovanni Manghi wrote:

there is hope see

https://trac.osgeo.org/grass/ticket/2592

I'm not sure that this new flag in r.mapcalc can help us.

Hi Médéric,

I've tested this in Windows (QGIS 2.14 OSGeo4W 64bits, with GRASS 7.0.3)

1) Load the raster_1.tif file (attached) to QGIS canvas;

2) Open r.mapcalc;

3)
3.1) Select "raster_1" on Multiple selection window;
3.2) Expression: raster_2 = raster_1 * 2
3.3) Select results directory

and I get

Algorithm r.mapcalc - Raster map calculator. starting...
g.proj -c proj4="+proj=tmerc +lat_0=39.66825833333333 +lon_0=-8.133108333333334 +k=1 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs" 
r.in.gdal input=D:\\Testes\\sample_raster\
aster_1.tif output=raster_1 --overwrite -o
g.region -a n=137550.0 s=112250.0 e=100125.0 w=74200.0 res=25.0
r.mapcalc expression="raster_2=raster_1*2" --overwrite
for r in $(g.list type=rast); do
r.out.gdal input=${r} output=D:\\Testes\\sample_raster/${r}.tif createopt="TFW=YES,COMPRESS=LZW" --overwrite
done

C:\\OSGeo4W64\\bin>set HOME=C:\\Users\\pedro 

C:\\OSGeo4W64\\bin>set GISRC=C:\\Users\\pedro\\.qgis2\\\\processing\\processing.gisrc7 

C:\\OSGeo4W64\\bin>set GRASS_SH=C:\\OSGeo4W64\\apps\\msys\\bin\\sh.exe 

C:\\OSGeo4W64\\bin>set PATH=C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>set WINGISBASE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3 

C:\\OSGeo4W64\\bin>set GISBASE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3 

C:\\OSGeo4W64\\bin>set GRASS_PROJSHARE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\share\\proj 

C:\\OSGeo4W64\\bin>set GRASS_MESSAGE_FORMAT=plain 

C:\\OSGeo4W64\\bin>if "" == "" set PATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>if not "" == "" set PATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>set GRASS_VERSION=7.0.0 

C:\\OSGeo4W64\\bin>if not "" == "" goto langset 

C:\\OSGeo4W64\\bin>FOR /F "usebackq delims==" %i IN (`"C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\winlocale"`) DO @set LANG=%i 

C:\\OSGeo4W64\\bin>set PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY 

C:\\OSGeo4W64\\bin>set PYTHONPATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\python;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\wxpython\

C:\\OSGeo4W64\\bin>g.gisenv.exe set="MAPSET=PERMANENT" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="LOCATION=temp_location" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="LOCATION_NAME=temp_location" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="GISDBASE=C:\\Users\\pedro\\AppData\\Local\\Temp\\processinga01588b329db4c8ca1aaf4c7a1bce49a\\grassdata" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="GRASS_GUI=text" 

C:\\OSGeo4W64\\bin>g.proj -c proj4="+proj=tmerc +lat_0=39.66825833333333 +lon_0=-8.133108333333334 +k=1 +x_0=0 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs" 
Default region was updated to the new projection, but if you have multiple mapsets `g.region -d` should be run in each to update the region from the default 
Projection information updated 

C:\\OSGeo4W64\\bin>r.in.gdal input=D:\\Testes\\sample_raster\
aster_1.tif output=raster_1 --overwrite -o 
ATENÇÃO: Over-riding projection check 
Proceeding with import of 1 raster bands... 
Importing raster map ... 
0..3..6..9..12..15..18..21..24..27..30..33..36..39..42..45..48..51..54..57..60..63..66..69..72..75..78..81..84..87..90..93..96..99..100 

C:\\OSGeo4W64\\bin>g.region -a n=137550.0 s=112250.0 e=100125.0 w=74200.0 res=25.0 

C:\\OSGeo4W64\\bin>r.mapcalc expression="raster_2=raster_1*2" --overwrite 
r nÆo era esperado nesta altura. 

C:\\OSGeo4W64\\bin>for r in $(g.list type=rast); do 

C:\\OSGeo4W64\\bin>set HOME=C:\\Users\\pedro 

C:\\OSGeo4W64\\bin>set GISRC=C:\\Users\\pedro\\.qgis2\\\\processing\\processing.gisrc7 

C:\\OSGeo4W64\\bin>set GRASS_SH=C:\\OSGeo4W64\\apps\\msys\\bin\\sh.exe 

C:\\OSGeo4W64\\bin>set PATH=C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>set WINGISBASE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3 

C:\\OSGeo4W64\\bin>set GISBASE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3 

C:\\OSGeo4W64\\bin>set GRASS_PROJSHARE=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\share\\proj 

C:\\OSGeo4W64\\bin>set GRASS_MESSAGE_FORMAT=plain 

C:\\OSGeo4W64\\bin>if "" == "" set PATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>if not "" == "" set PATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGeo4W64\\apps\\msys\\bin;C:\\OSGeo4W64\\apps\\msys\\lib;c:\\osgeo4~1\\apps\\python27\\lib\\site-packages\\shapely-1.2.18-py2.7-win-amd64.egg\\shapely\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\DLLs;C:\\OSGEO4~1\\apps\\Python27\\lib\\site-packages\
umpy\\core;C:\\OSGEO4~1\\apps\\qgis-rel-dev\\bin;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\lib;C:\\OSGEO4~1\\apps\\grass\\grass-7.0.3\\bin;C:\\OSGEO4~1\\apps\\Python27\\Scripts;C:\\OSGEO4~1\\bin;C:\\Windows\\system32;C:\\Windows;C:\\Windows\\WBem;C:\\OSGEO4~1\\apps\\msys\\bin 

C:\\OSGeo4W64\\bin>set GRASS_VERSION=7.0.0 

C:\\OSGeo4W64\\bin>if not "" == "" goto langset 

C:\\OSGeo4W64\\bin>FOR /F "usebackq delims==" %i IN (`"C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\winlocale"`) DO @set LANG=%i 

C:\\OSGeo4W64\\bin>set PATHEXT=.COM;.EXE;.BAT;.CMD;.VBS;.VBE;.JS;.JSE;.WSF;.WSH;.MSC;.PY 

C:\\OSGeo4W64\\bin>set PYTHONPATH=C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\python;C:\\OSGeo4W64\\apps\\grass\\grass-7.0.3\\etc\\wxpython\

C:\\OSGeo4W64\\bin>g.gisenv.exe set="MAPSET=PERMANENT" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="LOCATION=temp_location" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="LOCATION_NAME=temp_location" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="GISDBASE=C:\\Users\\pedro\\AppData\\Local\\Temp\\processinga01588b329db4c8ca1aaf4c7a1bce49a\\grassdata" 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="GRASS_GUI=text" 
r nÆo era esperado nesta altura. 

C:\\OSGeo4W64\\bin>for r in $(g.list type=rast); do 
Converting outputs
Loading resulting layers
Algorithm r.mapcalc - Raster map calculator. finished

without results.

The problem appears to be in the loop:

C:\\OSGeo4W64\\bin>r.mapcalc expression="raster_2=raster_1*2" --overwrite 
r nÆo era esperado nesta altura. 

C:\\OSGeo4W64\\bin>for r in $(g.list type=rast); do 

C:\\OSGeo4W64\\bin>g.gisenv.exe set="GRASS_GUI=text" 
r nÆo era esperado nesta altura. 

C:\\OSGeo4W64\\bin>for r in $(g.list type=rast); do 

Thanks!

Hi,

I?m also struggling to get nay result (on both Windows and Linux) out of this new implementation of r.mapcalc. Or maybe is not yet completely ready?

Giovanni Manghi wrote:

Hi,

I?m also struggling to get nay result (on both Windows and Linux) out of this new implementation of r.mapcalc. Or maybe is not yet completely ready?

seems ok on linux after all (I didn't get immediately that the expression needs to be written in the form "output = ..."), but still not ok on Windows.

One question: is possible in expression to use letters instead of the input raster names?

Currently the command is quite cumbersome:

• rasters have to be selected in the interface anyway (quite pointless from user perspective)
• raster names have to be entered by hand, with no clue (the names in the interface are the labels, not the real names)
• the output layer is not loaded automatically

Should I fill individual tickets for these issues?

Alexander Bruy wrote:

Closing this, as now Processing has front-end to QGIS native raster calculator and GRASS 6 was removed.

Hi Alexander and Victor. I think if you agree that we should open a new bug ticket about GRASS7 r.mapcalc.

(native) GRASS6 had both r.mapcalc (the real raster calculator tool) and r.mapcalculator, the latter a python wrapper for r.mapcalc that made the use of the raster calculator very convenient, allowing refer to input maps with letters and to use any of the r.mapcalc operators.

r.mapcalculator was present in Processing GRASS6 provider but as it wasn't ported GRASS7 we have also lost access to GRASS raster calculator in Processing/GRASS7.

That was until Médéric RIBREUX implemented r.mapcalc in Processing/GRASS7. Problem is that this implementation is partly working (see above comments) and it would be nice to have the issues sorted, if possible.

Hi all,

I have seen your message about r.mapcalc and r.mapcalculator... Indeed, even if i have discovered GRASS in year 1996, i must say: r.mapcalculator made the use of the raster calculator very convenient, allowing refer to input maps with letters and to use any of the r.mapcalc operators.

I miss r.mapcalculator with QGIS/GRASS7...

I think i have found how to run "r.mapcalculator" inside Processing / GRASS 7 of QGIS 2.18.x under Windows 7 (64 bits)... I need some days to submit/transmit you my solution (my files).

I can study how to run again "r.mapcalc" if necessary, because i have the same error :
C:\\OSGeo4W64\\bin>r.mapcalc expression="raster_2=raster_1*2" --overwrite
r nÆo era esperado nesta altura.

C:\\OSGeo4W64\\bin>for r in $(g.list type=rast); do

where : "r nÆo era esperado nesta altura." give in my french language : "r tait inattendu..."

===============
For information, i can't load "Processing" with QGIS 2.99/Windows 7 (64 bits) <=> I have many errors... So, i will not be able to try r.mapcalc (and/or r.mapcalculor) with...

I miss r.mapcalculator with QGIS/GRASS7...

r.mapcalculator was not ported from GRASS6 to 7 (not a QGIS issue) and this is were the problem started. In GRASS6 that module/script provided a very convinient way to use r.mapcalc.

Victor had created a new raster calculator using native QGIS classes, for QGIS 3:

https://github.com/qgis/QGIS/pull/3779

But in QGIS 2.x, r.mapcalc is still a must needed algorithm, and Vaclav Petras, in GRASS mailing list [0], pointed to the new -l flag introduced in GRASS72, to list inputs and outputs, which can solve the original problem of r.mapcalc:

https://grass.osgeo.org/grass72/manuals/r.mapcalc.html
https://trac.osgeo.org/grass/ticket/2592
https://trac.osgeo.org/grass/changeset/67000

What do you think?

[0] http://osgeo-org.1560.x6.nabble.com/r-mapcalculator-and-r-mapcalc-td5308738.html

Markus Neteler wrote:

FYI: The new r.mapcalculator has been developed by Vaclav Petras:

https://trac.osgeo.org/grass/ticket/3431#comment:7

I tested in QGIS/master/Processing and works ok! this is a very good news indeed!

I've tested also in QGIS 2.18.25, both on Windows and Linux, and it works really well!

Thank you very much Vaclav Petras!

FYI: r.mapcalculator moved as r.mapcalc.simple to GRASS GIS trunk (see https://trac.osgeo.org/grass/ticket/3431 with change https://trac.osgeo.org/grass/changeset/73791).

After some testing it will go to GRASS GIS 7.6.

Thank you very much Markus!

I've been testing it (still as r.mapcalculator plugin) in QGIS 2.18.26 and 3.4.2 and it works like a charm!

I've missed it so much for a long time!