Hi everyone:

I hope this has an easy answer. I think I am not clear on how a grid must be defined. I have a irregular grid with x:-190 to 190, y:-470 to 470 and z:-0.2 to -2.0. All meters. Data were rotated with ROTCOORD-GSLIB, rotation was ang 1: y-x 120�, ang 2: y-z -15� and ang 3: x-z 7.5�. After that x:-409 to -475, y:-336 to 343 and y:-126 to 132. (I understand there is a re-scale). When applying back-rotated to rotated coordinates, the original coordinates are obtained. Using the rotated coordinates the grid for kt3d was:

20 -450 50 -nx, xmin, xsize

15 -350 50 -ny, ymin, ysize

7 -150 50 -nz, zmin, zsize

After applying back-rotated process I got: x: -552 to 578, y:-584 to 626 and z:-297 to 290.

This is, Z is out of scale of the original data!!!. I prepared a file which includes rotated coordinates of the original points and grid coordinates generated by kt3d and addcoord, and back-rotated all together. Coordinates of original data are ok, but grid continues out of scale, even if points are close in xy...

What I am doing wrong?

I will appreciate any advise

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