search for: tp3607080p3607134

Hi, How can I accomplish this in R. Example: I have the following data.frame: data <- data.frame(x=c(1,2,3,4,5,6,5,3,7,1,0,4,8),y=c(1,2,1,2,2,2,1,1,1,2,2,2,2),z=c(5,8,4,3,4,1,6,3,3,6,3,5,7)) Supposing that data$y is a factor, I would like to find the Spearman correlation between data$x and data$z indexing it by data$y. To be more specific, I want to find two correlations: between x and z