double error syms code

syms x t a

%a=1/2;

N=3;

U=zeros(1,2,'sym');

A=zeros(1,2,'sym');

B=zeros(1,2,'sym');

series(x,t)=sym(zeros(1,1));

U(1)=simplify(1+sin(x));

%alpha=input('enter the value of alpha=')

%case1

% for i=1:8

% U(i+1)=simplify((diff(U(i),x,2)+U(i))*gamma(a*(i-1)+1)/gamma((a*(i+1-1))+1));

% end

for i=1:3

A=0;

for j=1:i

A=A+U(j)*U(i-j+1);

end

U(i+1)=simplify((diff(U(i),x,2)-A(1))

end

disp(U)

for k=1:2

series(x,t)=simplify(series(x,t)+U(k)*(power(t,a*(k-1))));

end

series

% C=zeros(1,1);

% series

C=zeros(1,1);

for x=1:3

e=(x-1)/10;

for t=1:6

f=((t-1)/10);

C(x,t)=series(e,f);

end

end

The following error occurred converting from sym to double:

Unable to convert expression into double array.

Error in fractionakelingordanequation (line 33)

C(x,t)=series(e,f);

[Mitchell Thurston]

it looks like this particular function is undefined at (0,0), so you might have some issues with that loop

Answer 1

[Steven Lord]

Preallocate C to be a sym array.

syms x  
C=zeros(3, 6, 'sym')

C = 

C(2, 3) = x.^2

C =