Using integrate() and function with if loop

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I am trying to numerically integrate the square of the density of a generalized extreme value distribution. So far I have tried this (partly based on the dgev function of the evd package):

So far I have this

f <- function(x){
  z <- (x - loc)/sc 
  if (sh == 0) {t <- log(1/sc) - z - exp(-z); return(exp(t)^2)}
  else if (sh*z < 0) {return(0)}
  else {t <- (1 + sh*z); return(exp(log(1/sc) - t^(-1/sh) - (1/sh + 1)*log(t))^2)}
}

loc <- 10; sc <- 2; sh <- 0
integrate(f, -Inf, Inf, rel.tol = 1e-6)$value   # no error message

loc <- 10; sc <- 2; sh <- 0.1
integrate(f, -Inf, Inf, rel.tol = 1e-6)$value   # error message

As indicated in the code, if sh is not 0, I get an error message, saying that

Fehler in integrate(f, -Inf, Inf, rel.tol = 1e-06) : 
evaluation of function gave a result of wrong length
Zusätzlich: Warnmeldung:
In if (sh * z < 0) { :
Bedingung hat Länge > 1 und nur das erste Element wird benutzt
Fehler in integrate(f, -Inf, Inf, rel.tol = 1e-06) : 
evaluation of function gave a result of wrong length

Why does this happen?

I have also tried using the dgev function from the evd package in integrate, this works fine, but I would like to understand what I have done wrong in my code.

Thanks for your help in advance

asked 38 secs ago

user3825755

3

Using integrate() and function with if loop