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Grid Arithmetics

In one grid file up to four evaluation parameters plus a ground grid can be saved. Those grids can be referred to using the following expressions:

R0 refers to the current grid with all defined evaluation parameters. A grid arithmetics would effect all grids of all evaluation parameters.
R01 to R04 refers to the current grid, just for one the defined evaluation parameters 1 to 4
R0g refers to the current ground grid
R1 refers to a saved grid loaded to input box R1 and effects the grids of all evaluation parameters
R11 to R14 refers to the grid loaded to input box R1, just for one the defined evaluation parameters 1 to 4
R1g refers to the ground grid loaded to input box R1
R3 to R6 analogously as described above
R1@V1 refers the grid of all evaluation parameters in variant 1, loaded to input box R1
R11@V1 bis R14@V1 refers the grid of one of the evaluation parameters 1 to 4 in variant 1, loaded to input box R1
R61@V16 bis R64@V16 refers the grid of one of the evaluation parameters 1 to 4 in variant V16, loaded to input box R6

Grids can be addressed either by the capital character „R“ or by the lower-case character „r“.

Examples

Variable Explanation
r0+1 adds to value 1 to the current grid (for all 4 resulting grids when the respective check-boxes are deactivated)
r01+1 adds the value 1 to the for evaluation parameter 1 of the current grid
r1--r0 subtracts energetically the current grid r0 from the loaded input grid r1 (for up to 4 evaluation parameters 1 to 4)
r0++r1 sums up energetically the current grid r0 and the loaded input grid r1 (for up to 4 evaluation parameters 1 to 4)
r01-r1g subtracts the ground grid of the grid which has been loaded for input grid R1 (r1g) from the current grid of evaluation parameter 1 (r01)
r01++r13 sums up energetically the evaluation parameter 1 of the current grid R0 and the evaluation parameter 3 of the grid loaded into R1
r02--r14 subtracts energetically the evaluation parameter 2 of the current grid R0 and the evaluation parameter 4 of the grid loaded into R1

Grid Variable OK

By the grid variable OK it can be evaluated for each grid point how its value was determined. The grid variable OK may receive the following values:

  • 0 = invalid
  • 1 = calculated
  • 2 = interpolated
  • 3 = extrapolated

Example

Variable Explanation
iif(r0ok==3, invalid, r0) This expression sets all extrapolated grid points to „invalid“ (e.g. for grid points below buildings). This may result in „gaps“ in a noise map.