Symbolic summation within a for-loop

I have a function that is dependent on two variables, f(j, k). I would like to create a loop that, for each j, sums the function for each value of k. I have tried the code:

for j=1:10;
g(j)=symsum(f(j,k), k, 1, 10);
end;

However, I get an error message "Undefined function 'symsum' for input arguments of type 'double'." on running the code. What is the best way to do the above in MATLAB?

[Azzi Abdelmalek]

How f is defined?

Answer 1

[Walter Roberson]

symsum cannot use the summation variable to index.

If f is not vectorized then you use

sum( arrayfun(@(k) f(j, k), 1:10) )

If f is vectorized you might be able to use

 sum( f(j, 1:10) )

but you might need

sum( f(repmat(j,1,10), 1:10) )

depending on how f is coded.

Answer 2

[Azzi Abdelmalek]

Look at this example

syms  f j k 
f=j*sin(k)
for jj=1:10;
  ff(k)=subs(f,j,jj);
  s=symsum(ff(k), k, 1, 10);
  g(jj)=double(s)
end;