MATLAB: Trying to make symsum work.

code_errorMATLABSymbolic Math Toolboxsymsum

I am having problems getting symsum to calculate the following sumation within this equation:
example.PNG
I am using the following code to get pi:
function piram
  %approximates and prints pi with Ramanujan's formula
  %called as piram or piram()
  %doesn't return a value, but a print
  
  k=sym('k');
  sumpart=symsum((factorial(4*k)*(1103+26390*k))/(((factorial(k))^4)*(396^(4*k))),k,0,inf);
  inverted=sumpart*((2*sqrt(2))/9801);
  approxpi=1/inverted;
  fprintf('Using Ramanujan''s formula, a good approximation is %.6f\n',approxpi)
end
Can anyone help with this?

Best Answer

If the only factorial function that appears when you execute:
which -all factorial
is the one included in MATLAB, you probably don't have Symbolic Math Toolbox installed. Check the output of the ver function to test whether you have it installed. If you don't have Symbolic Math Toolbox installed, I would have expected the sym or syms calls to error before you even reached the line where you called symsum, but it's possible you've written your own functions named sym or syms that are being used instead of the versions from Symbolic Math Toolbox.
If what you posted in response to madhan ravi's question was the output of which factorial (without the -all flag) try it with the -all flag and show us what that returns.
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