I don't think there's a cunning way to do it.  It demands a minimum of 2 
comparisons, max 3. Sorting 4 or more you'd want to use a function call or 
you'd have a lot of messy and confusing code (this is confusing enough). 
Best pseudo code I can do:

                  IF B >= A GOTO BA
                  IF C >= A GOTO A                ; A > B if C >= A then C 
 >= A > B
                  IF C >= B GOTO C                ; A > B and A > C if C >= 
B  then A > C >= B
                                                                  ; A > B, A 
 > C and B > C therefore A > B > C
B               ANSWER B
                  GOTO END
BA             IF C >= A GOTO BACA        ; B >= A
                                                                  ; B >= A > 
C
A               ANSWER A
                  GOTO END
BACA       IF C >= B GOTO B                 ; B > A, C > A if C >= B then C 
 >= B > A
                                                                  ; B > A, C 
 > A and B > C therefore B > C > A
C               ANSWER C
END

 Regards,

Dan


----- Original Message ----- 
From: "Mark Rages" <markrages@gmail.com>
To: <piclist@mit.edu>
Sent: Saturday, July 16, 2005 6:26 AM
Subject: [PIC] Design Challenge: Find center of three values


> Here's a design challenge for you guys:
>
> I have values in three file registers:  fileA, fileB, fileC.
>
> I want to choose the value that's in the middle (numerically) and put it 
> into W.
>
> The brute-force way to do this would be to copy the list, sort the
> copy in place, and choose the middle value.
>
> I'm sure there's a more direct way.  Any ideas?
>
> (Application:  This a simple nonlinear filter to remove occasional
> outliers in a sampled data stream.)
>
> Regards,
> Mark
> markrages@gmail
> -- 
> You think that it is a secret, but it never has been one.
>  - fortune cookie
>
> -- 
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
> 

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist