[R] How to calculate the product of every two elements in two lists?

[Dennis Murphy]

Hi:

Here's a slightly different approach:

# Create two numeric matrices with outer():
o1 <- outer(u,u,">=") * 1L
o2 <- outer(v, v, ">=") * 1L

# Make a list of matrices that multiplies column i of o1
# vs. each column of o2 - use the * operator to do this
# Shows what is going on at each step:
lapply(seq(ncol(o1)), function(s) o1[, s] * o2)

# Concatenate all product columns together into a matrix:
do.call(cbind, lapply(seq(ncol(o1)), function(s) o1[, s] * o2))

HTH,
Dennis

On Mon, Jun 13, 2011 at 6:23 AM, carla moreira <carlamgmm at gmail.com> wrote:
>
> u<-c(0.1,0.2,0.3)
> v<-c(0.2,0.3,0.5)
>
> outer1<-outer(u,u,">=")
> outer2<-outer(v,v,">=")
> m<-nrow(outer1)
> j<-nrow(outer2)
> zz<-lapply(1:m, function(m) as.numeric(outer1[m,]))
> tt<-lapply(1:m, function(m) as.numeric(outer2[m,]))
>
> zz[[1]]*tt[[3]], e.g., is possible, but I want every products between two
> lists.
>
> Is there a way to do that?
>
> --
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