File takes as input vector of points (lat/lon) and coastal resolution and returns vector of indicators for whether these points are over land or ocean. Makes geographic plot too, if desired.

Primary code was given in a response to a question by Brett Shoelson in Feb 2011://www.tatmou.com/matlabcentral/answers/1065-determining-whether-a-point-on-earth-given-latitude-and-longitude-is-on-land-or-ocean
As far as I can tell, this code has not been put into a function file for public use.