[R] an SJava array question
Rajarshi Guha
rxg218 at psu.edu
Wed May 26 22:44:35 CEST 2004
Hi,
I'm using SJava (0.65) to interface some Java code I have and am
having trouble understanding the use of arrays. I have a function:
tmv <- function(fname) {
a <- .JavaArrayConstructor("int", dim=c(3,0))
.JavaSetArrayElement(a, .JavaArrayConstructor("int", dim=3), 1)
.JavaSetArrayElement(a, .JavaArrayConstructor("int", dim=3), 2)
.JavaSetArrayElement(a, .JavaArrayConstructor("int", dim=3), 3)
for (i in 1:3) {
for (j in 1:3) {
.JavaSetArrayElement(a, as.integer(i*j), i,j)
}
}
print(.JavaGetArrayElement(a, 1,1))
}
I expect that I should see 1 print out but instead I get
[[1]]
[1] 1 2 3
[[2]]
[1] 1 2 3
The SJava manual seems to indicate that .JavaGetArrayElement(a, 1,1)
gives the first element of the first array.
Could anybody throw some light on this?
A related question is the an array of Strings.
Does .JavaArrayConstructor("String",3) give me an array of 3 Strings
(which are not yet defined) or a String of length 3? Or if I need to
allocate an array of Strings should I do:
r <- .JavaArrayConstructor( "String", c(3,0) )
and then for each element of r add a new array and then finally set the
individual elements to the actuial string values?
Is there any example code available that I could take a look at?
Thanks,
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Rajarshi Guha <rxg218 at psu.edu> <http://jijo.cjb.net>
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