R help - Oct 2005 - Error in integrate

I'm using R 2.0.1 under Windows XP. I get the following message when I 
run the code listed below. I don't seem to have any problems using the 
function "slice" outside "integrate".

Error in integrate(slice, 0, Inf, , , , , , , a, b) * delta :
         non-numeric argument to binary operator

[ By the way, I'm trying to evaluate a two-dimensional integral by 
slicing it up into one-dimensional bits which I will loop over to evaluate.]

Here's the code:

mu <- 0.3
sig2 <- 0.01
alpha <- 20
beta <- 15.75
rho <- 0.1
k <- 1/(rho^2.5*gamma(rho)^2*sqrt(2*pi*sig2))

slice <- function(w,a,b)
{
  g <- w^(1/rho)
  g1 <- w1^(1/rho)
  h <- g1^a*g^b
  E <- -(y-rho*mu -g1/alpha + g/beta)^2/(2*sig2*rho)
  k*h*exp(E- g1 - g)
}

hi <- 10
delta <- 0.05
grid <- seq(delta/2,hi,delta)
y <- -0.3
a <- 0
b <- 0
m <- length(grid)
A <- rep(0,m)
j <- 0

for (w1 in grid)
{
  j <- j+1
  A[j] <- integrate(slice,0,Inf,,,,,,,a,b)*delta
  cat(A[j],"\n")
}


-- 
Dr Murray Jorgensen      http://www.stats.waikato.ac.nz/Staff/maj.html
Department of Statistics, University of Waikato, Hamilton, New Zealand
Email: maj at waikato.ac.nz                                Fax 7 838 4155
Phone  +64 7 838 4773 wk    Home +64 7 825 0441    Mobile 021 1395 862

Murray Jorgensen <maj at stats.waikato.ac.nz> wrote:
> I'm using R 2.0.1 under Windows XP. I get the following message when I 
> run the code listed below. I don't seem to have any problems using the 
> function "slice" outside "integrate".
> 
> Error in integrate(slice, 0, Inf, , , , , , , a, b) * delta :
>          non-numeric argument to binary operator
> 
RTFM!  Integrate returns:
Value:

     A list of class '"integrate"' with components
     :
     :

You need:
A[j] <- integrate(slice,0,Inf,,,,,,,a,b)$value*delta

Ray