r - Technical error of measurement (TEM) for 3 or more participants -

i need implement formula r function. surprise there no r packages tem function 3 or more participants. me out?

here go

# m : data frame of different measurements tem <- function(m) {     nrows <- nrow(m)     ncols <- ncol(m)     sqrt(sum(apply(m,1,function(x) sum(x^2) - sum(x)^2/ncols))/(nrows*(ncols-1))) } 

here's example

child_data <- data.frame(     height_a=c(64.50,71.00,58.00,58.00,70.50,69.00,63.00,65.00,62.00,68.00),     height_b=c(64.00,71.50,59.00,58.00,71.50,67.50,64.00,64.50,62.00,68.00) )  tem(child_data) # 0.5477 

this figure presented in paper referenced.

then, example (three columns)

child_data$height_c <- c(63.5,71.3,59.0,58.5,71.4,67.4,64.2,64.50,62.5,67.5) tem(child_data) # 0.5