integrate function

Hi All,

Can any one help to explain why min and max function couldn't work in the
integrate function directly.

For example, if issue following into R:

integrand <- function(x) {min(1-x, x^2)}
integrate(integrand, lower = 0, upper = 1)

it will return this:
Error in integrate(integrand, lower = 0, upper = 1) :
   evaluation of function gave a result of wrong length


However, as min(U,V) = (U+V)/2-abs(U-V)/2

Below code working;

integrand <- function(x){(1-x+x^2)/2-0.5*abs(1-x-x^2)}

integrate(integrand, lower = 0, upper = 1)

0.151639 with absolute error < 0.00011

I am confused...


Dan

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