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making a `data.frame` out of any two same-name variables in two larger data.frames in R

Using a looping structure in BASE R, I was wondering how I could make a data.frame out of any two same-name variables in data.frames X and Y and then table each data.frame?

Without a looping structure, my R code is:

X <- data.frame(R = rbinom(20, 1, .4), B = rbinom(20, 3, .3), N = rbinom(20, 5, .7))
Y <- data.frame(R = rbinom(20, 1, .4), B = rbinom(20, 3, .3), N = rbinom(20, 5, .7))

 table(data.frame(X$R, Y$R))

 table(data.frame(X$B, Y$B))

 table(data.frame(X$N, Y$N))
Solution

  • We can use Map to create the table of corresponding columns of 'X' and 'Y'

    Map(table, X, Y[names(X)])

    If we need to have the levels same

    Map(function(x, y) table(factor(x, levels = 0:5), 
                factor(y, levels = 0:5)), X, Y[names(X)])