How to keep the same class?

Hello



Please see the example below

class(testX)

[1] "matrix"

class(testX[1,])

[1] "numeric"



Why not matrix?   What am I missing here?   Is there a way to keep the same
class?   



The reason for the question is that I want to implement a k-step ahead
prediction for my own routines and R wrecks does not seem to like [1,] as
shown below.

predict(fit10,testX[1,])

Error in knnregTrain(train = c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  : 
 dims of 'test' and 'train differ

predict(fit10,testX[1:2,])

[1] 81.00 76.36



Many thanks



Ed