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Hi Hella,
Only a few of the transformations are calculated in multiple
dimensions. Most apply the operation one direction at a time as
you're seeing here. For transformations in
general,
Transformations are normally computed axis by axis;
if multiple axes have transformations specified simultaneously
(e.g., U[Z=@AVE,L=@SBX:10]) the transformations
will be applied sequentially in the order X then Y then Z then
T. ...
only averages and definite integrals are computed using multiple
dimensions, as they involve area calculations, and NGD and NBD also
count over all dimensions given. So yes, the filling
transformations fill in X then in Y, etc.
Ansley
On 6/28/2018 7:37 AM, Hella Riede
wrote:
Hello
ferret community,
I am using @FNR in two dimensions and got an unexpected result
(see ferret script at end of this mail):
In the attached ferret_before_FNR.png, the original 2D grid cells
are shown (values inherited from dots by scat2grid, see below).
ferret_after_FNR.png shows the result after applying @FNR (fill
with nearest neighbor) in 2 dimensions.
As an example for the unexpected result, lets take the grid cell
at (x=8,y=5). Its value before @FNR was undefined. The nearest
neighbor is (x=8,y=8). Yet, the value is inherited from (x=2,y=4).
Is @FNR not supposed to be applied in 2D or is the logic behind
different from what I expected? It seems the missing points are
always filled up in x dimension first, and only remaining missing
values are then filled up in y direction ...
I attached a manual version of what I would have expected as
ferret_FNR_expected.png.
Thank you very much in advance for helping to clarify this.
Best regards,
Hella Riede
can var/all
can sym/all
let a = {1,1,8,8,2}
let b = {1,8,8,1,4}
let val = {2,4,6,8,10}
def ax/x=1:8:1 xax
def ax/y=1:8:1 yax
def sym lev = (1.5,10.5,1)
!! assign values from dots to grid cells
set win 1
let gridded =
SCAT2GRIDGAUSS_XY(a,b,val,x[gx=xax],y[gy=yax],0.8,0.8,0.8,0)
shade/lev=($lev) gridded
!! plot original scattered values for comparison
go polymark poly/lev=($lev)/key/ov/line/fill a b val circle 2
!! fill up undefined values with nearest neighbor
set win 2
let nn = gridded[x=@FNR,y=@FNR]
shade/lev=($lev) nn
go polymark poly/lev=($lev)/key/ov/line/fill a b val circle 2
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