describe.numeric(x,num.desc=c("mean","median","var","sd","valid.n"),
 varname="",vname.space=10,fname.space=10)num.desc.describe.numeric displays the name of the vector and the
 results of the functions whose names are passed in num.desc.
 Note that any functions that are called by describe.numeric
 must have an na.rm argument, even if it is a dummy.describe, valid.n