[Bug] v.rast.stats reports same numbers for number and null_cells (winGRASS) about grass

[hellik]

steps to reproduce in NC sample data set

• g.region -a raster=elev_ned_30m@PERMANENT align=elev_ned_30m@PERMANENT

• v.in.region output=myregion

• quick digitize 1 polygon covering a small part of elev_ned_30m, e.g. mymask

• r.mask vector=mymask@user1

• r.mapcalc expression="test = elev_ned_30m@PERMANENT"

• r.mask -r

• v.rast.stats map=myregion@user1 raster=test@user1 column_prefix=zs

[hellik]

easier, just use the example from the v.rast.stat manual, just choose only number and null_cells in method:

v.rast.stats map=myzipcodes_wake@user1 raster=elevation@PERMANENT column_prefix=elev method=number,null_cells

v.db.select map=myzipcodes_wake@user1 columns=cat,OBJECTID,NAME,elev_number,elev_null_cells where=cat = 12 OR cat = 13
cat|OBJECTID|NAME|elev_number|elev_null_cells
12|17|RALEIGH|43980|43980
13|19|RALEIGH|135806|135806

elev_number and elev_null_cells shows the same figures

[hellik]

maybe related:

v.rast.stats: addition of null_cells count - 26ae605

[hellik]

easy testing by

g.region -p -a raster=elevation@PERMANENT align=elevation@PERMANENT             
projection: 99 (Lambert Conformal Conic)
zone:       0
datum:      nad83
ellipsoid:  a=6378137 es=0.006694380022900787
north:      228500
south:      215000
west:       630000
east:       645000
nsres:      10
ewres:      10
rows:       1350
cols:       1500
cells:      2025000

v.in.region output=myregion@user1

v.centerpoint input=myregion@user1 output=myregion_cp

v.buffer input=myregion_cp@user1 output=myregion_cp_buffer_250m distance=250

r.mask vector=myregion_cp_buffer_250m@user1

r.mapcalc expression="mytestraster = elevation@PERMANENT"

r.mask -r

v.db.addtable map=myregion@user1

v.rast.stats map=myregion@user1 raster=mytestraster@user1 column_prefix=elev method=number,null_cells

v.db.select map=myregion@user1                                                  
cat|elev_number|elev_null_cells
1|1944|1944 <=

r.univar -e map=mytestraster@user1                                              
total null and non-null cells: 2025000
total null cells: 2023056 <=
Of the non-null cells:
----------------------
n: 1944 <=
minimum: 108.462
maximum: 130.415
range: 21.9533
mean: 121.157
mean of absolute values: 121.157
standard deviation: 4.39815
variance: 19.3437
variation coefficient: 3.63013 %
sum: 235528.598342896
1st quartile: 118.196
median (even number of cells): 121.278
3rd quartile: 124.69
90th percentile: 126.597

total null cells: 2023056 by r.univar vs. 1944 by v.rast.stats

[hellik]

manually r.univar test with the 2 rasters

r.univar map=mytestraster@user1 zones=myregion_raster@user1                     
zone 1 
total null and non-null cells: 2025000 <=
total null cells: 2023056  <=
Of the non-null cells:
----------------------
n: 1944
minimum: 108.462
maximum: 130.415
range: 21.9533
mean: 121.157
mean of absolute values: 121.157
standard deviation: 4.39815
variance: 19.3437
variation coefficient: 3.63013 %
sum: 235528.598342896

total null cells: 2023056 correctly counted in contrary to 1944 by v.rast.stats

[ninsbl]

Backported in 94c2dc2 and 787f55e