Question

I’m using R to complete some GA driven searches.

Returned from my GA script is the resulting chromosome, returned as a binary numeric of length 40.

An example is: c(0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0).

I also have a corresponding data frame with 40 columns.

Using the data in the numeric vector, how do I efficiently build a (or re-build the) data frame so that it contains only those columns represented by the 1’s in my numeric vector?

Answer 1

Building a sample data.frame and assigning your sample vector to x:

df <- as.data.frame(matrix(sample(1:100, 400, replace=T), ncol=40))
x <- c(0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0)

I can subset:

df[ ,x==1]

or:

df[, as.logical(x)]