Plot an equation (sigma operator)

Hi everyone,

I would like to plot this equation for x=[-2,2] and x=3, I wrote this code but it ain't working. Could you please tell me how can I make it work ? Thanks in advance.

clc
clear 
close all


H=0
 for x=-2:0.1:2;
 n=3;
   for k=0:floor(n/2); 
   H=H+((-1)^k)*factorial(n)*(x^(n-2*k))/(2^k*factorial(k)*factorial(n-2*k));
   end
 end


x=-2:0.1:2;
plot(x,H,'r')

Answer 1

[Star Strider]

Try soemthing like this —

n=3;
kv=0:floor(n/2);
xv=-2:0.1:2;
H = zeros(size(xv));
Hv = zeros(size(xv));
 for k2 = 1:numel(xv)
    x = xv(k2);
   for k1 = 1:numel(kv)
       Hv(k1) = ((-1)^kv(k1))*factorial(n)*(x^(n-2*kv(k1)))/(2^kv(k1)*factorial(kv(k1))*factorial(n-2*kv(k1)));
   end
   H(k2) = sum(Hv);
 end


x=-2:0.1:2;
plot(x,H,'r')

The ‘H’ variable was being saved as a scalar, not a vector.

.

Answer 2

[Fatemeh Salar]

Dear @Star Strider ;

Thank you so much =)

[Star Strider]

As always, my pleasure!