MATLAB: Relatively simple problem with matrix and loops

for loopMATLABmatrix

 i got a problem with a script and is described next:
this is the script that i'm preparing. Is focused to clip a topography in several parts (Topoclip1, Topoclip2… Topoclipi) based on polygons included in a shapefile.
The main problem is the loop, i dont know what's happen when i try to run the scripts the results is (??? Subscripted assignment dimension mismatch.)
 %%Inputs
 clear
 addpath /Users/mac/Documents/MATLAB/intersection/stat1
 stationsdir='/Users/mac/Documents/MATLAB/intersection/stat1';
 a=load('topo.txt');  %load the raster (previously grided xyz table)
 cd(stationsdir)
 %cd(station)
 station='stat'; 
 file=sprintf('%s_clip.shp',station); 
 p=shaperead(file);  
 nim=numel(p);
 % Extract rectangular profile corners for each profile
 for i=1:nim
    data=p(i,1); %for the current extention of data...
    x=data.X; %extract x values from shapefile
    x=x'; %transpose elements

    x(end)=[];
    y=data.Y; %extract y values from shapefile
    y=y'; %transpose elements
    y(end)=[]; 
    xy=[x y]; %conform the resulting matrix
    xy(end,:)=[]; %delete the redundating last row and fix a 4 vertices polygon
   %to here all works ok... the problems is placed somewhere in the next lines
    taga=num2str(i);
    v = genvarname(['Prof' taga]);
    eval([v '=xy']);
    Xp=xy(:,1); %rectangular profile X coordinate
    Yp=xy(:,2); %rectangular profile Y coordinate
    Xt= a(:,1); %Lon1
    Yt= a(:,2); %Lat1
    h= a(:,3);
    %in = inpolygon(Xt,Yt,Xp,Yp);
    %plot(Xp,Yp,x(in),Yt(in),'r+')
    [loni,lati] = polybool('intersection',Xt,Yt,Xp,Yp);
    [lati loni];
    A(:,1)=a(:,1);
    A(:,2)=a(:,2);
    A(:,3)=a(:,3);
    B(:,1)=loni';
    B(:,2)=lati';
    out=A(ismember(A(:,1:2),B,'rows'),:);
    taga=num2str(i);
    v = genvarname(['Topoclip' taga]);
    eval([v '=out']);
    %scatter(Topoclip1(:,1), Topoclip1(:,2),20,Topoclip1(:,3),'filled')
end
the ides is to obtain an i number of Topoclip (ie: Topoclip1, Topoclip2, Topocli3….) eachone formed by the clipped topography.
Please give me a hand…. if you can…
thanx

Best Answer

If you run the following, you have the same problem. The error usually tells you which line of the code did the error happen. So check the assignment inside the loop to see how it happens. You can put a break point in the code and run the code line by line
a=rand(3);
a(:,1)=1:5
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