how to estimate/evaluate the integral of a constant value function?

For example, f = 5, for 0<t<1, zero otherwise.

i tried the following code but it didn't work:

syms t
f = 10;
int(f)

Answer 1

[Walter Roberson]

syms t a b real
f = piecewise(0 < t & t < 1, 5, 0)

f = 

int(f, t, a, b)

Warning: Unable to check whether the integrand exists everywhere on the integration interval.

ans = 

[Jinquan Li]

thanks. this works. Now i have another question. What if i use numerical integration? Here is what i tried:

f1 = @(t) piecewise(0<t & t<1, 10, 0);

q = integral(f1,0,1)

Answer 2

[Just Manuel]

Try this:

syms t
f = 0*t + 10;
int(f);

Cheers Manuel

[Jinquan Li]

Thank you! What if i use numerical integration?

[Just Manuel]

you can't use piecewise in a numerical context. redefine your function as follows:

f = @(t) 5 .* (t > 0 & t < 1);

% then you can calculate numerical integral like this
integral(f, -1, 1)

Cheers

Manuel

[Jinquan Li]

Thanks a lot! this works!