 
The region setting will not effect the memory consumption of this module. The number of subranges in case of value range calculation or the number of equal value groups effect the memory consumption and the calculation time. The user can expect a huge time consumption to calculate the equal value groups (flag -e) if large region settings occur for maps which have many equal value groups (> 100000).
  num   |        value       |     volume    |   perc  |    count
      1             1.000000   300822000.000   50.13700        50137
      2             2.000000   101400000.000   16.90000        16900
      3             3.000000   197778000.000   32.96300        32963
      4                    *           0.000   0.00000            0
Number of groups with equal values: 3
Sum of non Null cells:
        Volume = 600000000.000
        Percentage = 100.000
        Count = 100000
Sum of all cells:
        Volume = 600000000.000
        Percentage = 100.000
        Count = 100000
#create a small 3D region
g.region n=1000 s=0 e=2000 w=0 t=300 b=0 res3=100
#create a raster3D map with row() and null values
r3.mapcalc "volmap = if(row() == 5, null(), row())"
#run r3.stats with a subrange of 10
r3.stats input=volmap nsteps=10
#the result should look like this
 num   | minimum <= value   | value < maximum    |     volume    |   perc  | cell count
      1          1.000000000          1.900000000    60000000.000   10.00000           60
      2          1.900000000          2.800000000    60000000.000   10.00000           60
      3          2.800000000          3.700000000    60000000.000   10.00000           60
      4          3.700000000          4.600000000    60000000.000   10.00000           60
      5          4.600000000          5.500000000           0.000   0.00000            0
      6          5.500000000          6.400000000    60000000.000   10.00000           60
      7          6.400000000          7.300000000    60000000.000   10.00000           60
      8          7.300000000          8.200000000    60000000.000   10.00000           60
      9          8.200000000          9.100000000    60000000.000   10.00000           60
     10          9.100000000         10.000000001    60000000.000   10.00000           60
     11                    *                    *    60000000.000   10.00000           60
Sum of non Null cells:
        Volume = 540000000.000
        Percentage =  90.000
        Cell count = 540
Sum of all cells:
        Volume = 600000000.000
        Percentage = 100.000
        Cell count = 600
Available at: r3.stats source code (history)
Latest change: Wednesday Nov 27 22:53:26 2024 in commit: b90ce69e88409469369ec1edb86fde8ec822af8b
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