Im trying to use 4 point gauss quadrature method and this is my code and getting errors any help T^T?

Im trying to use 4 point gauss quadrature method and this is my code and getting errors any help T^T?

when i run it im getting statement imcomplete error at line 17

sum=sum+eval(func) * wt(i)

format long
func='(exp(x)*sin(x)/(1+x^2)';
xa=0.0;
xb=3.0;

ngp = 4;
xi(1) = -0.8611363116;  wt(1) = 0.3478548451;
xi(2) = -0.3399810436;  wt(2) = 0.6521451549;
xi(3) = -xi(1);         wt(3) = wt(1);
xi(4) = -xi(2);         wt(4) = wt(2);

coeff = (xb-xa)/2.0;

sum = 0.0;
for i=1:ngp
    x = (xb+xa)/2.0 + (xb-xa)/2.0 *xi(i);
    sum = sum + eval(func)*wt(i);
end
sum = sum * coeff;
[sum]

[Walter Roberson]

Missing ) in func

[Park Jihoon]

my gosh so embarassed haha

guess late night working doesnt help at all

if i run this it gives me sum=2.881695213604899

however if i integrate the function form 0 to 3

my ti gives me 0.123147

does that mean my program is faulted?

[David Wilson]

Your code seems reasonable,

>> f = @(x) exp(x).*sin(x)./(1+x.^2);
>> integral(f,0,3)
ans =
    2.8816

Although you might want to double check your integrand since there is more than one way to insert a bracket.

Can't explain the TI response though.

[Park Jihoon]

thanks man great help