This function allows the user to create data structures that are paneled or cross-classified: where one level of observation draws simultaneously from two or many source levels. Common examples of panels include country-year data which have country-level and year-level characteristics.
cross_levels(by = NULL, ...) link_levels(N = NULL, by = NULL, ...)
Arguments
| by | The result of a call to |
|---|---|
| ... | A variable or series of variables to add to the resulting data frame after the cross-classified data is created. |
| N | The number of observations in the resulting data frame.
If |
Value
data.frame
Details
By specifying the appropriate arguments in join() within the
function call, it is possible to induce correlation in cross-classified data.
Examples
# Generate full panel data panel <- fabricate( countries = add_level(N = 20, country_shock = runif(N, 1, 10)), years = add_level(N = 20, year_shock = runif(N, 1, 10), nest=FALSE), obs = cross_levels(by=join(countries, years), GDP_it = country_shock + year_shock) ) # Include an "N" argument to allow for cross-classified # data. students <- fabricate( primary_school = add_level(N = 20, ps_quality = runif(N, 1, 10)), secondary_school = add_level(N = 15, ss_quality = runif(N, 1, 10), nest=FALSE), students = link_levels(N = 500, by = join(primary_school, secondary_school)) ) head(students)#> primary_school ps_quality secondary_school ss_quality students #> 1 15 9.265041 09 6.544130 001 #> 2 06 6.860068 08 9.282482 002 #> 3 11 1.629510 05 8.978955 003 #> 4 09 9.849402 12 7.921122 004 #> 5 07 5.758383 14 5.847698 005 #> 6 07 5.758383 06 6.400336 006# Induce a correlation structure in cross-classified data by providing # rho. students <- fabricate( primary_school = add_level(N = 20, ps_quality = runif(N, 1, 10)), secondary_school = add_level(N = 15, ss_quality = runif(N, 1, 10), nest=FALSE), students = link_levels(N = 500, by = join(ps_quality, ss_quality, rho = 0.5)) ) cor(students$ps_quality, students$ss_quality)#> [1] 0.4551475