I have a Surfer grid where the minimum value is -9999.99. How can I change the minimum value to 0?

You can change the minimum value of a grid file to 0 using Grid Math. To do this:

  1. Click Grids | Calculate | Math.
  2. In the Grid Math dialog, click the Add Grids button, select the grid file and click Open.
  3. Specify a new name for the Output Grid, if desired.
  4. Enter the function max(A,0) to replace all negative values with 0, or you can use the function IF(A=-9999.99, 0, A) to specifically replace only -9999.99 with 0 (leaving other negative values alone)
  5. If you want to add the new grid to the active project check Add grid as layer to:, select either [New Map] or [Map], and select the layer type in the New layer type drop down menu.
  6. Click OK and the new grid file is created.


Updated October 22, 2018

Was this article helpful?
0 out of 0 found this helpful
Have more questions? Submit a request


Please sign in to leave a comment.