data column sorting in R

Here is my dataset.

set.seed (1234) mydf <- data.frame (Id = c("dis", 1:5), V1.a = c(0,sample(c(0, 1,2), 5, replace = T)),V1.b = c(0,sample(c(0, 1,2), 5, replace = T)), V2.a = c(1.5,sample(c(0, 1,2), 5, replace = T)),V2.b = c(1.5,sample(c(0, 1,2), 5, replace = T)), V3.a = c(2.0,sample(c(0, 1,2), 5, replace = T)),V3.b = c(2.0,sample(c(0, 1,2), 5, replace = T)), V4.a = c(5.0,sample(c(0, 1,2), 5, replace = T)),V4.b = c(5.0,sample(c(0, 1,2), 5, replace = T)), V5.a = c(6.0,sample(c(0, 1,2), 5, replace = T)),V5.b = c(6.0,sample(c(0, 1,2), 5, replace = T)), V16a = c(11.0,sample(c(0, 1,2), 5, replace = T)),V6.b = c(11.0,sample(c(0, 1,2), 5, replace = T)), V7.a = c(12.0,sample(c(0, 1,2), 5, replace = T)),V7.b = c(12.0,sample(c(0, 1,2), 5, replace = T)), V8.a = c(3.0,sample(c(0, 1,2), 5, replace = T)),V8.b = c(3.0,sample(c(0, 1,2), 5, replace = T))) d = mydf > d Id V1.a V1.b V2.a V2.b V3.a V3.b V4.a V4.b V5.a V5.b V16a V6.b V7.a V7.b V8.a 1 0 0 0 1.5 1.5 2 2 5 5 6 6 11 11 12 12 3 2 1 1 2 1.0 0.0 1 2 1 2 0 1 1 2 0 1 1 3 2 1 1 2.0 2.0 1 2 0 1 0 1 1 1 0 2 0 4 3 0 0 1.0 2.0 2 0 2 2 2 2 2 1 1 2 0 5 4 0 2 0.0 2.0 2 2 1 1 2 2 2 1 2 1 0 6 5 2 1 2.0 0.0 2 0 1 1 0 1 0 0 0 2 1 V8.b 1 3 2 2 3 0 4 2 5 0 6 2 

I wanted to order by value in first row element of each variable.

> d <- d[,order(d[1,-1])] > d Id V1.a V1.b V2.a V2.b V3.a V7.b V8.a V3.b V4.a V4.b V5.a V5.b V16a V6.b V7.a 1 0 0 0 1.5 1.5 2 12 3 2 5 5 6 6 11 11 12 2 1 1 2 1.0 0.0 1 1 1 2 1 2 0 1 1 2 0 3 2 1 1 2.0 2.0 1 2 0 2 0 1 0 1 1 1 0 4 3 0 0 1.0 2.0 2 2 0 0 2 2 2 2 2 1 1 5 4 0 2 0.0 2.0 2 1 0 2 1 1 2 2 2 1 2 6 5 2 1 2.0 0.0 2 2 1 0 1 1 0 1 0 0 0 

Ordering is not working for V7.a! V8.a is missing. What is the problem or good way to do it some other way?