the array index is not matching

syms x  mu  gamma
syms t %c
alpha=1
U=zeros(1,2,'sym')
V=zeros(1,2,'sym');
A=zeros(1,1,'sym');
B=zeros(1,1,'sym');
C=zeros(1,1,'sym');
D=zeros(1,1,'sym');
series1(x,t)=sym(zeros(1,1));
series2(x,t)=sym(zeros(1,1));
%%%%%%%%%%%%%%%%%%%%%  initial condition
%mu=1
U(1)=mu*exp(1i*x)
V(1)=gamma*exp(1i*x)
u=conj(U(1))
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
for m=1
    A(1)=0;
    B(1)=0;
    for j=1:m
        for k=1:j
            A(1)=A(1)+U(k)*V(j-k+1)*conj(V(m-j+1));
            B(1)=B(1)+V(k)*U(j-k+1)*conj(U(m-j+1));
        end
    end
    U(m+1)=gamma(((m-1)*alpha)+1)/gamma((alpha*(m+1-1))+1)*1i*(1i*diff(U(m),x,1)+V(m)+A(1))
    V(m+1)=gamma(((m-1)*alpha)+1)/gamma((alpha*(m+1-1))+1)*(-1i*diff(V(m),x,1)+U(m)+B(1))
end

Index exceeds the number of array elements. Index must not exceed 1.

Error in indexing (line 936)

R_tilde = builtin('subsref',L_tilde,Idx);

why it showing the error ? As I will compute diff(U(m),x,1)+V(m)+A(1)) . The index in each term will be 1 .

[yogeshwari patel]

Thanks

Answer 1

[Vinay]

Hi @yogeshwari patel,

The issue is due to the 'gamma' variable which is being used both as a symbolic variable and as a function in the below code

U(m+1)=gamma(((m-1)*alpha)+1)/gamma((alpha*(m+1-1))+1)*1i*(1i*diff(U(m),x,1)+V(m)+A(1))
V(m+1)=gamma(((m-1)*alpha)+1)/gamma((alpha*(m+1-1))+1)*(-1i*diff(V(m),x,1)+U(m)+B(1))

The above code treats 'gamma' as a function and causing the error.The workaround is to use the multiplication operator after the variable 'gamma' in the expression

U(m+1)=gamma*(((m-1)*alpha)+1)/gamma*((alpha*(m+1-1))+1)*1i*(1i*diff(U(m),x,1)+V(m)+A(1))
V(m+1)=gamma*(((m-1)*alpha)+1)/gamma*((alpha*(m+1-1))+1)*(-1i*diff(V(m),x,1)+U(m)+B(1))

I hope this helps!