Nearneighbor search radius

I would like to use gmt nearneighbor with a non-circular search radius (applied to non-geographic xy data), i.e. the equivalent of setting an anisotropic aspect ratio in gmt surface. Is this possible?

GMT6.1 (currently GMTdev) has a new module called grdgal that should let you do that. The key is going to be passing the correct gdal options in -F option.

Looks like nearneighbor is computing a circle radius, which for Cartesian data with different x and y meanings might be odd. You may be able to get what you want to scaling your y data coordinates such that a circle radius of r ends up needing N nodes in x but M nodes in y, effectively using an ellipse instead of a circle.