How To read or write the real component of a complex grid in GMT ?.
Read and write are two rather different operations. What is it that you are trying to read? And what for?
I have applied an arcsinus function to a grid containing values greater than ±1. To avoid complex parts appearing in the result, I want the final grid to contain only real values.
Don’t know what GMT does in those circumstances but it won’t write an imaginary grid. The simplest way to solve your issue is to use grdclip to insure data is on a valid domain.