R help - Apr 2006 - lm$effects in lm()

Hi ..
  
     lm() returns an effects component in its output. I read the explanation in
R but was not quite clear.
  
  say my response is Y
  and design matrix is X
  
  say X has QR decomposition X=QR
  
  is effects = Q (Q'Q)^-1 Q' Y  ???
  
  i am sure this is wrong as it did not match the output from lm() . what is the
actual calculation.
  
  Harsh.
  
  
		
---------------------------------

	[[alternative HTML version deleted]]