Array indexes must be positive integers or logical values.

this is the code that what i input but

Array indexes must be positive integers or logical values. at the moment SUM= E1*SUM(V(3:IOUT+1,JOUT+2))....

+E1*V(2,JOUT+2)/2+E2*V(IOUT+2,2)/2;

what is the problem?

clear all;format compact;
%Output;
%
%     H      NT      Zo
%  -----------------------
%   0.25    700    69.77
%   0.1     500    65.75
%   0.05    500    70.53
%   0.05    700    67.36
%   0.05   1000    65.50

H=0.05;
NT= 100;

A=2.5; B=2.5; D=0.5; W=1.0;

ER=2.35;
EO=8.81E-12;
U=3.0E+8;

NX=A/H;
NY=B/H;
ND=D/H;
NW=W/H;
VD=100.0;
ERR=1.0;
    E1=EO;
    E2=EO*ERR;
   
%CALCULATE CHARGE WITH AND WITHOUT DIELECTRIC
 L=1:2
    E1=EO;
    E2=EO*ERR;
    
%INITIALIZATION
    V=zeros(NX+2,NY+2);
    
%SET POTENTIAL ON INNER CONDUCTOR(FIXED NODES) EQUAL TO VD 
V(2:NW+1,ND+2)=VD;


    
   
     %NOW,CALCULATE THE TOTAL CHARGE ENCLOSED IN A 
     %RECTANGULAR PATH SURROUNDING THE INNER CONDUCTOR
     
     IOUT=round((NX+NW)/2);
     JOUT=round((NY+ND)/2);
     
     %SUM POTENTIAL ON INNER AND OUTER LOOPS
     for K=1:2
         SUM=0;
         SUM= E1*SUM(V(3:IOUT+1,JOUT+2))....
             +E1*V(2,JOUT+2)/2+E2*V(IOUT+2,2)/2;
         for J=1:JOUT-1
             if(J<ND)
                 SUM=SUM+E2*V(IOUT+2,J+2);
             elseif(J==ND)
                 SUM=SUM+(E1+E2)*V(IOUT+2,J+2)/2;
             else
                 SUM=SUM+E1*V(IOUT+2,J+2);
             end
         end
         if K==1
             SV(1)=SUM;
         end
         IOUT=IOUT-1;
         JOUT=JOUT-1;
     end
     SUM=SUM+2.0*E1*V(IOUT+2,JOUT+2);
     SV(2)=SUM;
     Q(L)=abs(SV(1)-SV(2));
     ERR=ER;

% FINALLY,CALCULATE Zo
Co=4.0*Q(1)/VD;
C1=4.0*Q(2)/VD;
ZO=1.0/(U*sqrt(C0*C1));
disp([H,NT,ZO])

Answer 1

[Alan Stevens]

Looks like you are using SUM when you want sum. Change to:

SUM= E1*sum(V(3:IOUT+1,JOUT+2))....

Also, in line 59, you should have C0 not Co.

[ljaseon]

Thank you i got it!