Hello,
You are making a confusion between
1. the formal argument log.p
2. the variable log.p
In the function body, log.p is a variable that exists in the function's
frame, not the formal argument of pnorm.
The first and the 3rd calls that follow output the same value.
try(x = 1.2, log.p = TRUE)$a
try(x = 1.2, log.p = TRUE)$b
try(x = 1.2, 1)$a
This is because in the function
a<-pnorm(x,log.p) # first call
passes log.p as the *second* argument, not as a value for pnorm's formal
argument log.p. Unless when named, the arguments are passed in the order
they appear in the function's definition:
pnorm(q, mean = 0, sd = 1, lower.tail = TRUE, log.p = FALSE)
and that becomes
a<-pnorm(x,TRUE) # first call
a<-pnorm(x,1) # first call, coerced to numeric.
Let me give another example. In the function that follows the default is
z = FALSE.
In the first call the name z is not the name of the argument, it's the
name of a variable that exists in the .GlobalEnv.
In the second call, z = z assign the formal argument z the value of the
variable z.
f <- function(x, y = 0, z = FALSE){
a <- x
b <- y
d <- z
list(a = a, b = b, d = d)
}
z <- 2
f(1, z)
f(1, z = z)
Hope this helps,
Rui Barradas
Às 11:11 de 20/09/20, Steven Yen escreveu:
Can someone tell me a proper call to a procedure, in this case, pnorm.
In what follows, I had expected a = b, but they are not equal. What are
wrong with first call and second call? Thank you!
try<-function(x,log.p=FALSE){
a<-pnorm(x,log.p) # first call
b<-pnorm(x,log.p=log.p) # second call
list(a=a,b=b)
}
try(x=1.2,log.p=TRUE)$a
try(x=1.2,log.p=TRUE)$b
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______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
