help, im getting the following error: error using zeros size input must be scalar

% data
S=70; n=10; K=100; r=0.05; delta=0.10; sigma=0.2; dt=1; d=4; b=50;
 
% allocate storage
syms j x
for j=1:1:d
    w(j)=j;
end
 
for i=1:1:b
    j=1:1:d;
    v(i,j)=i+j;
end
 
% initialize parameters
v(1,1) = S;
w(1) = 1;
v=zeros(j+1,n);
for j = 2:1:d
    v(i,j) = S(i,j)*exp(((r-delta-(sigma)^2)/2)*dt+sigma*(sqrt(dt*randn)));
    w(j) = 1;
end 
 
% process tree
j = d;
while (j > 0)
    switch j
    case 1 
        v=zeros(j+1,n);
        for j=1:n
        v(w(j),j) = max(max((S-K),0),exp(-r*max(S-K,0)));
        v(w(j)+1,j) = S(w(j),j)*exp(((r-delta-(sigma)^2)/2)*dt+sigma*(sqrt(dt*randn)));
        w(j) = w(j)+1;
        end
        
        case 2
            v(w(j),j) = max(max((S-K),0),exp(-r*max(S-K,0)));
            w(j)=0;
            j=j-1;
            
        case 3 
            v=zeros(j+1,n);
            v(w(j),j)=max(max((S-K),0),(symsum((1/b)*exp(-r*max((S-K),0)),j,1,b)));
            if (j>1)
            for j=1:n
                v(w(j)+1,j)=S(w(j),j)*exp(((r-delta-(sigma)^2)/2)*dt+sigma*(sqrt(dt*randn)));
                w(j)=w(j)+1;
                for i=j+1:1:d
                    v(i,j)=S(w(j),j)*exp(((r-delta-(sigma)^2)/2)*dt+sigma*(sqrt(dt*randn)));
                    w(i)=1;
                end
                j=d;
            else
                j=0;
            end
            end
            
        case 3 
            v(w(j),j)=max(max((S-K),0),(symsum((1/b)*exp(-r*max((S-K),0)),j,1,b)));
            w(j)=0;
            j=j-1;
    end
end

[KSSV]

There is other error then the mentioned one. Error with else......check your code.

Answer 1

[Walter Roberson]

for i=1:1:b
  j=1:1:d;

That code sets j to be a vector. Later you try to use j+1 as the first parameter to zeros(). You can only pass a vector to zeros if the vector is the only numeric input.

It is unlikely that you want to use a vector for j at that point.