function [xy,distance,t_a] = distance2curve(curvexy,mapxy,interpmethod)
% distance2curve: minimum distance from a point to a general curvilinear n-dimensional arc
% usage: [xy,distance,t] = distance2curve(curvexy,mapxy) % uses linear curve segments
% usage: [xy,distance,t] = distance2curve(curvexy,mapxy,interpmethod)