You can do it with get()
and ls()
:
'A1-pre' <- matrix(rnorm(100), 5)
'B3-pos' <- matrix(rnorm(100), 5)
'B4-pre' <- matrix(rnorm(100), 5)
'C5-not' <- matrix(rnorm(100), 5)
names <- grep('pre|pos$', ls(), value=T)
newDF <- mapply(get, grep('pre|pos$', ls(), value=T))