How to define a variable which is numerical and changes in every cycle of the while loop?

Hello.

I have a code that in a part of it there is a while loop, which is shown as below:

 while all(DIST((1:ncities),(1:ncities))<realmax)
        [mindist,nextcity]= min(newDIST(currentcity,:))
        while [xi yi]>0 & [xi yi]== all(nextcity*(1:2))==0
            [xi,yi,ii]=polyxpoly(outxd,outyd,all([currentcity;nextcity],1),all([currentcity;nextcity],2));
            [row, col]=find(all(:,1)==transpose(z(ii(:,1),1)));
            vec=[row,row+1];
            [mindistedge,nextcity]=min(newDIST(vec,currentcity));
            nextcity=vec(nextcity);
        end
        traveleddist=traveleddist+DIST(currentcity,nextcity)
 end
 

I defined all the matrix in the first part when I run the code I got an error "xi" in not defined,so here is my question how can I define xi and yi which changes in each cycle of the loop and I need the loop to run untile there is no intersection between lines.

Thanks for your help in advance.

Answer 1

[Rik]

You should not have an array input to an if or while. Your second conditional could do with some edits.

To solve your actual problem, you will have to assign a value to the variables that make sure you enter the loop.