%分幀函數
function?f=enframe（xwininc）
%?F?=?ENframe（XLEN）?splits?the?vector?X（:）?up?into
%?frames.?Each?frame?is?of?length?LEN?and?occupies
%?one?row?of?the?output?matrix.?The?last?few?frames?of?X
%?will?be?ignored?if?its?length?is?not?divisible?by?LEN.
%?It?is?an?error?if?X?is?shorter?than?LEN.


nx=length（