distanceparandperp.m

％ ％ set some variables in the workspace to control behaviour: ％ ％ graphicsMode 0 no graphics, ％

% Here's how this function is called in latLongErrorLoop:
% [per, par] = distanceParAndPerp(KF(i,2), KF(i,3), GT(i,2), GT(i,3), GT(i,4));

function [per, par]= distanceParAndPerp(xp, yp, xc, yc, alpha)


%[per, par]= distanceParAndPerp(xp, yp, xc, yc, alpha)
%xp,yp subject point
%xc,yc one point on the line
%alpha direction of the line
%finds the distances from (xp,yp) to the line at alpha through (xc,yc).

stop=min(size(xp,1),size(xc,1));
xp = xp(1:stop);
xc = xc(1:stop);
yp = yp(1:stop);
yc = yc(1:stop);
alpha=alpha(1:stop);
%vector from c to p
vx = xp-xc;
vy = yp-yc;
%vector from c to inf at alpha
vux = cos(alpha);
vuy = sin(alpha);

cross = vx.*vuy-vy.*vux;
dot   = vx.*vux+vy.*vuy;
% %perpendicular distance
% per = abs(cross);
% %parallel distance
% par = abs(dot);


%perpendicular distance
per = (cross);
%parallel distance
par = (dot);