MATLAB: Error while using Symsum

symsum

Error using sym/symsum (line 54)

Unable to compute sum with respect to '1'. Summation index must be a symbolic variable.

Error in TIMEVARRYINGMAIZECOBSON2112020 (line 175)

fvalue(1,s) = symsum(f5,s,0,g1)- symsum(f2,s,0, 1)-symsum(f3,s,0, 1)-symsum(f4,s,0, g1) %-symsum(f5,0, gbest(1,s));

here the value of g1= gbest(s,1)

Your variable s has value 1, but what you pass in the second position for symsum() must be a scalar symbolic variable.

syms u
 % ^-—-— missed s at the end

t=1:99;
syms s k
y=double(subs(symsum(1/(k-1),s+1,100) ,t) );
plot(t,y)