Fill Grid Dummies Using Spline (NGAPFILL)

Use the Fill Grid Dummies using Spline option (NGAPFILL GX) in the GM-SYS 3D Tools > Manual FFT Preparationmenu to replace dummy values in a grid with linear, periodic values.

Fill Grid Dummies using Spline dialog options

Input grid file	Select the input grid with dummies to be filled.
Output grid file	Output grid with no dummy values.
Percent dummy cut-off	Skips grid rows with more than this % of dummy values on the first pass. Defaults to 50.

Application Notes

The GX (ngapfill.gx) first examines the grid by rows. It fills "interior" dummy values using an Akima spline.

If the row still contains more than percent dummy cut-off dummies, it does not fill the edges of the row.

If the % of dummies in the row is less than or equal to the percent dummy cut-off value, it fills the edges of the row with values interpolated linearly from the last value on the left to the first value on the right.

After processing the grid by rows, it goes through the grid by columns using a similar scheme but ignoring the "percent dummy cut-off".