Comparing gamstransfer Objects

Equivalence between two symbols or between two containers can be tested using equals method. Since the order of records in the records data frame is not important from a GDX point of view, equals method compares symbol records independently from the order in which they are stored in the records data frame. As this requires a merge operation over the domain columns, equals is a computationally expensive call.

Note

We do not recommend using equals method inside large loops or when performance is critical. It is, however, very useful for data debugging.

A quick example shows the syntax of equals:

library(gamstransfer)
m <- Container$new()
i <- Set$new(m, "i", records = paste0("i", 1:5), description = "set i")
j <- Set$new(m, "j", records = paste0("i", 1:5), description = "set j")

> i$equals(j)
[1] FALSE

One can debug the reason for inequality using the option verbose.

> i$equals(j, verbose=TRUE)
Symbol names do not match i != j
[1] FALSE

By default, equals takes the strictest view of symbol “equality”, i.e., everything must be equal. In this case, the symbol names and descriptions differ between the two sets i and j. We can relax this with a combination of argument flags. Comparing the two symbols again, but ignoring the meta data (i.e., ignoring the symbol name, description and type (if a Variable or Equation)):

> i$equals(j, checkMetaData=FALSE)
[1] TRUE

The checkUELs argument will ensure that the symbol “universe” is the same (in order and content) between two symbols, as illustrated in the following example:

library(gamstransfer) m <- Container$new() i <- Set$new(m, “i”, records = c(“i1”, “i2”, “i3”)) ip <- Set$new(m, “ip”, records = c(“i1”, “i3”, “i2”))

> i$equals(ip, checkMetaData=FALSE)
[1] FALSE

> i$equals(ip, checkMetaData=FALSE, checkUELs=FALSE)
[1] TRUE

Numerical comparisons are enabled for Parameters, Variables and Equations. Equality can be flexibly defined through the equals method arguments. Again, the strictest view of equality is taken as the default behavior of equals.

library(gamstransfer)
m <- Container$new()
i <- Set$new(m, "i", records = c("i1", "i2", "i3"))
a <- Parameter$new(m, "a", i, records = data.frame(c("i1", "i2", "i3"), c(1, 2, 3)))
ap <- Parameter$new(m, "ap", i, records = data.frame(c("i1", "i2", "i3"), c(1 + 1e-9, 2, 3)))

> a$equals(ap, checkMetaData=FALSE)
[1] FALSE

> a$equals(ap, checkMetaData=FALSE, verbose=TRUE)
Symbol records contain numeric differences in the value attribute that are outside the specified tolerances
            rtol=0, atol=0

> a$equals(ap, checkMetaData=FALSE, atol=1e-8)
[1] TRUE

In the case of variables and equations, it is possible for the user to confine the numerical comparison to certain attributes (level, marginal, lower, upper and scale) by specifying the columns argument as the following example illustrates:

library(gamstransfer)
m <- Container$new()
a <- Variable$new(m, "a", "free", records = data.frame(level = 100))
ap <- Variable$new(m, "ap", "free", records = data.frame(level = 101))

> a$records
level
1   100

> ap$records
level
1   101

> a$equals(ap, checkMetaData=FALSE)
[1] FALSE

> a$equals(ap, checkMetaData=FALSE, columns="level")
[1] FALSE

> a$equals(ap, checkMetaData=FALSE, columns="marginal")
[1] TRUE

Similar to symbols, one can compare two Container objects using the equals method. When comparing Containers, the data fields are compared and if the same symbol keys exist in the Containers under comparison, symbol equals method is used to compare the symbols. Here is a brief example:

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

m1 <- Container$new()
i1 <- Set$new(m1, "i")

> m$equals(m1)
[1] TRUE

> j = Set$new(m1, "j")

> m$equals(m1)
[1] FALSE

> m$equals(m1, verbose=TRUE)
Error in m$equals(m1, verbose = TRUE) :
Containers contain different number of symbols.
self: 1
other :2

> k = Set$new(m, "k")

> m$equals(m1)
[1] FALSE

> m$equals(m1,verbose=TRUE)
Error in m$equals(m1, verbose = TRUE) :
Container ``data`` field keys do not match. Keys not present in ``other`` :k