The “as….” explicitly converts the data to whatever you desired outcome.
 as.array(x)
 as.data.frame(x)
 as.numeric(x)
 as.logical(x)
 as.vector(x)
 as.matrix(x)
 as.complex(x)
 as.character(x)
 … convert type; for a complete list, use methods(as)
to one long vector 
to matrix 
to data frame 

from vector 
c(x,y)  cbind(x,y) rbind(x,y) 
data.frame(x,y) 
from matrix 
as.vector(mymatrix)  as.data.frame(mymatrix)  
from data frame 
as.matrix(myframe) 
If you are interested in testing data types use “is…” instead of “as…” this will allow R to return a TRUE or FALSE outcomes.