Plotting truncated FS expansion

For the following Y[k], I want to plot y(t) between and :

Where L, C are constants that I've already defined.

I'm trying this:

t=linspace(-pi*10^-3,pi*10^-3);

syms k
y = symsum((1/pi * i * 1000 * sin(pi*k/2))/(1/C + i*1000*k + L(i*1000*k).^2) * exp(i*k*1000*t),k,-99,99);

Which gives the following error:

Invalid indexing or function definition. Indexing must follow MATLAB indexing. Function arguments must be symbolic variables, and function body must be sym expression.

Answer 1

[Ayush Gupta]

The following code is implemented with the assumption of C and L to be 1 as they are constants and it works fine and plots the graph of y.

t=linspace(-pi*10^-3,pi*10^-3);

syms k

y = symsum((1/pi * 1i * 1000 * sin(pi*k/2))/(1 + 1i*1000*k + (1i*1000*k).^2) * exp(1i*k*1000*t),k,-99,99)

plot(t,y)