Ncontributors function

Find the number of unique groups contributing to aggregates

Assuming aggregates are calculated via a dummy matrix by z = t(x) %*% y, the the number of unique contributing groups, according to a grouping variable, are found for each aggregate. The missing group category is not counted.

Ncontributors(x, groups)

Arguments

• x: A (sparse) dummy matrix
• groups: Vector of group categories

Returns

Vector of numbers of unique groups

Examples

library(SSBtools)

z <- SSBtoolsData("sprt_emp_withEU")
z$age[z$age == "Y15-29"] <- "young"
z$age[z$age == "Y30-64"] <- "old"
z$groups <- c("A", "A", "B", "A", "B", "C")

a <- ModelMatrix(z, formula = ~age*eu + geo + year, crossTable = TRUE)

cbind(as.data.frame(a$crossTable), nGroups = Ncontributors(a$modelMatrix, z$groups))
cbind(as.data.frame(a$crossTable), nYears = Ncontributors(a$modelMatrix, z$year))
cbind(as.data.frame(a$crossTable), nUnique_ths_per = Ncontributors(a$modelMatrix, z$ths_per))

See Also

ModelMatrix

Author(s)

Øyvind Langsrud