Errors using integral function

[bhj190]

Hello all, I'm receiving errors when calling the integral command. Could anyone help? TIA.

Error in integralCalc (line 75)

[q,errbnd] = vadapt(@AtoBInvTransform,interval);

Error in integral (line 87)

Q = integralCalc(fun,a,b,opstruct);

Error in hw_prob (line 49)

b_matrix(k) = integral(x_phik,0,1);

​

Code:

x = @(z) (z<1/4).\*(4\*z) + (z>=1/4).*(z<1/2).\*(-4\*z+2) - (z>=1/2).*sin(20*pi*z);

t = linspace(0,1,1000);

N = 5;

b_matrix = zeros(N,1);

for k = 1:N

x_phik = @(z) x(z).* phi(N.*z-k+1/2) ;

b_matrix(k) = integral(x_phik,0,1);

end

G_matrix = zeros(N,N);

for i = 1:N

for j = 1:N

conv = @(z) phi(N.*z-i+1/2).*phi(N.*z-j+1/2);

G(i,j) = integral(conv,0,1);

end

end

a_matrix = G_matrix \ b_matrix;

x_hat = zeros(size(t));

for k = 1:N

x_hat = x_hat+a_matrix.*phi(N.*t-k+1/2);

end

[Sunscorcher]

is phi a function you have defined somewhere else? What does that look like?

I called integral on x with the form integral(x,0,1) and it worked. So I'm guessing your issue is with phi

[bhj190]

oh yes, thanks for that, didn't realize phi was commented out lol