[R] Converting a function from Splus to R

[Freddy Hernández]

I have a function written for Splus, when I run it in R I obtain get an error
because the function has the elements "0.d0" and "2.d0". How can I change it
to run in R?

The function can be found in page 230 from
 http://www.stat.wisc.edu/~mchung/teaching/stat471/stat_computing.pdf

Function is as follows:

gauher <- function(n) {# Gauss-Hermite: returns x,w so that
#\int_-\infty^\infty exp(-x^2) f(x) dx \doteq \sum w_i f(x_i)
EPS <- 3.e-14
PIM4 <- .7511255444649425D0
MAXIT <- 10
m <- trunc((n+1)/2)
x <- w <- rep(-1,n)
for (i in 1:m) {
if (i==1) {
z <- sqrt(2*n+1)-1.85575*(2*n+1)^(-.16667)
} else if(i==2) {
z <- z-1.14*n^.426/z
} else if (i==3) {
z <- 1.86*z-.86*x[1]
} else if (i==4) {
z <- 1.91*z-.91*x[2]
} else {
z <- 2.*z-x[i-2]
}
for (its in 1:MAXIT) {
p1 <- PIM4
p2 <- 0.d0
for (j in 1:n) {
p3 <- p2
p2 <- p1
p1 <- z*sqrt(2.d0/j)*p2-sqrt((j-1)/j)*p3
}
pp <- sqrt(2.d0*n)*p2
z1 <- z
z <- z1-p1/pp
if(abs(z-z1) <= EPS) break
}
x[i] <- z
x[n+1-i] <- -z
w[i] <- 2/(pp*pp)
w[n+1-i] <- w[i]
}
list(x=x,w=w)
}

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