Fri, 28 Aug 2009, 22:00

As student writes:



	To: patt@ece.utexas.edu
	Subject: Question about Turing "black boxes" for Problem Set 1
	Date: Fri, 28 Aug 2009 15:28:12 -0500

	Hello,

	I am ***************, a student in your EE 306 class but I have come  
	across an issue I hope you are able to clarify rather easily. I  
	understand the concept of the input-output as stated in the text but  
	it was not clearly stated whether an arbitrary value can be used as an  
	input rather than a variable. 



There is no restriction on the value that can be applied as an input to
a black box.  It can be a constant (that is, a specific value) or it can
be a variable (where the specific value is dependent on the data that is
being processed).



	My question pertains to Question 2b, the  
	average of w,x,y, and z. It is easy to do with ...



I have deleted the student's first steps in his solution in order to not
deny the rest of you the pleasure of doing it yourselves.



	but to find the average, you would need a constant value as an 
	input to one of the black boxes.  This is okay with me but in 
	none of the examples was  anything like that shown and I felt 
	unsure whether it was "illegal" because there would be no way 
	to "input" the constant and thus losing the  programability 
	which I believe is the very point of the exercise.



Actually, the programmability is not compromised, since there are many
programs that rely on constant values (generally part of the program
as it is written) and not on values read in as input.  In the case of
our black box, this corresponds to simply using a specific constant as 
an input to one of the black boxes.



	Thanks,
	<<name withheld to protect ...>>

	P.S. I absolutely love your teaching style



Thank you for the compliment.  I hope you feel the same way in December.
Good luck with EE 306.

Yale Patt