[R] integrate function

[Prof. Dr. Matthias Kohl]

use pmin instead of min.
hth
Matthias

On 12.02.2013 16:41, dan wang wrote:
> 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
>
> 	[[alternative HTML version deleted]]
>
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-- 
Prof. Dr. Matthias Kohl
www.stamats.de