TRSbook (version 1.0.4)

getaddr: Retrieve the address in memory of a variable

Description

Retrieve the address in memory of a numeric variable

Usage

getaddr(x)

Value

Integer value of the address of x

Arguments

x

numeric

Author

Lafaye de Micheaux Pierre <[e-mail]>, Remy Drouilhet <[e-mail]>, Liquet Benoit <[e-mail]>

References

Chapter 9 (Managing Sessions) from the book: The R Software, Fundamentals of Programming and Statistical Analysis

Examples

# \donttest{
x <- c(8L,9L)
addr <- getaddr(x) # Gets the address of the first
                            # box of the 64-box block where x
                            # is stored.
addr
writeaddr(addr,6L) # Write the integer 6 at this address.
x
writeaddr(addr+4L,7L) # An integer is coded over 4 bytes,
                      # hence increment the address by 4 to
                      # get to x[2].
x
x <- c(12.8,4.5)
x
addr <- getaddr(x) # Get the address of the first box
                            # of the 128-box block where x is
                            # stored.
writeaddr(addr,6.2)
x
writeaddr(addr+8L,7.1) # A double is coded over 8 bytes.
x
# }