www.pudn.com > geometric.rar > pdist.m, change:2004-08-13,size:2266b

function [d,xhat,yhat]=pdist(x,y,xnot,ynot) % d=pdist(x,y,xnot,ynot) % % pdist computes the perpendicular distance between the the straight line % represented by the points (x(1),y(1)) & (x(2),y(2)) and the third point % (xnot,ynot). (xhat,yhat) is the point of intersetion between the % perpendicular and the straight line. % % NOTE: It is illegal for you to use this software for a purpose other % than non-profit education or research UNLESS you are employed by a CREWES % Project sponsor. By using this software, you are agreeing to the terms % detailed in this software's Matlab source file. % BEGIN TERMS OF USE LICENSE % % This SOFTWARE is maintained by the CREWES Project at the Department % of Geology and Geophysics of the University of Calgary, Calgary, % Alberta, Canada. The copyright and ownership is jointly held by % its author (identified above) and the CREWES Project. The CREWES % project may be contacted via email at: crewesinfo@crewes.org % % The term 'SOFTWARE' refers to the Matlab source code, translations to % any other computer language, or object code % % Terms of use of this SOFTWARE % % 1) Use of this SOFTWARE by any for-profit commercial organization is % expressly forbidden unless said organization is a CREWES Project % Sponsor. % % 2) A CREWES Project sponsor may use this SOFTWARE under the terms of the % CREWES Project Sponsorship agreement. % % 3) A student or employee of a non-profit educational institution may % use this SOFTWARE subject to the following terms and conditions: % - this SOFTWARE is for teaching or research purposes only. % - this SOFTWARE may be distributed to other students or researchers % provided that these license terms are included. % - reselling the SOFTWARE, or including it or any portion of it, in any % software that will be resold is expressly forbidden. % - transfering the SOFTWARE in any form to a commercial firm or any % other for-profit organization is expressly forbidden. % % END TERMS OF USE LICENSE if(abs(x(2)-x(1))>eps) m=(y(2)-y(1))/(x(2)-x(1)); b=y(1)-m*x(1); d=abs(m*xnot-ynot+b)/sqrt(m*m+1); xhat=(m*(ynot-y(1))+xnot+m*m*x(1))/(m*m+1); yhat=m*(xhat-x(1))+y(1); else xhat=x(1); yhat=ynot; d=abs(xhat-xnot); end