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function n = findclosest( x,y, x1,y1 )
% n = findclosest( x,y, x1,y1 )
% (x,y) are lists of coordinates, x(i) corresponds to y(i)
% (x1,y1) coordinates of point we're looking for 
% n location in list of closest point in (x,y) to (x1,y1)
%
% finds the coordinates nearest to input point,returns their location in
% the list of coordinates
% method: find minimum sum of squares of differences

xtemp = x - x1;
xtemp = xtemp .* xtemp;
ytemp = y - y1;
ytemp = ytemp .* ytemp;
temp = xtemp + ytemp;
[minval,n] = min(temp);