www.pudn.com > geometric.rar > distreach.m, change:2004-08-13,size:2937b

function [s,indicies]=distreach(x,y,xnot,ynot,r)  % [s,indicies]=distreach(x,y,xnot,ynot,r) % % This function searches the point set represented by x,y to find those points % which lie within a radius r of the single point xnot,ynot. The distances of % the found points are returned in s and their indicies in indicies. Thus, the % number of found points is length(s) and they are identified as: % x(indicies),y(indicies) is the set of points whose distances from xnot,ynot % are given by s <= r. % See also distcum distinc and distpoint % % x = vector containing the x coordinates of the data points % % y = vector containing the y coordinates of the data points % % xnot = scalar x coordinate of the single point % % ynot = scalar y coordinate of the single point % % r= radius of the search region (also called the reach) % % s = distance vector containing the distance between each point in %     x and y and the point xnot,ynot % % by G.F. Margrave, March 1993 % % 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  % do first sort xmin = xnot-r;xmax=xnot+r; ymin= ynot-r; ymax= ynot+r;  ind = find((x<=xmax)&(x>=xmin)); ind = find((y(ind)<=ymax)&(y(ind)>=ymin));  s=distpoint(x(ind),y(ind),xnot,ynot);  indicies = find( s<= r);  s=s(indicies); indicies=ind(indicies);