Alias

Adding Alias Records

The linked structure of Aliases offers some unique opportunities to access some of the setter functionality of the parent set. Specifically, GAMS Transfer allows the user to change the domain, description, dimension, and records of the underlying parent set as a shorthand notation. We can see this behavior if we look at a modified Example #1 from adding set records.

Example - Creating set records through an alias link

library(gamstransfer)
m <- Container$new()
i <- Set$new(m, "i")
ip <- Alias$new(m, "ip", i)

ip$description <- "adding new descriptive set text"
ip$domain <- c("*", "*")

ij <- list(paste0("i", 1:3), paste0("j", 1:3))
ip_recs <- rev(expand.grid(rev(ij)))
colnames(ip_recs) <- c("i", "j")
ip$setRecords(ip_recs)

> i$domain
[1] "*" "*"

> i$records
i  j
1 i1 j1
2 i1 j2
3 i1 j3
4 i2 j1
5 i2 j2
6 i2 j3
7 i3 j1
8 i3 j2
9 i3 j3

Note

An alias $isValid()=TRUE when the underlying parent set is also valid. If the parent set is removed from the Container the alias will no longer be valid.

Note

One can also use the generateRecords() method to automatically populate randomly generated symbol records in the standard format.