| Title: | Mathematics at DEC | 
| Moderator: | RUSURE::EDP | 
| Created: | Mon Feb 03 1986 | 
| Last Modified: | Fri Jun 06 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 2083 | 
| Total number of notes: | 14613 | 
 I get the following information from VPA and Monitor (?)
+-------------------------------------------------------------------+
| The following table gives a summary of the average amount of lock |
| traffic per second in the cluster.                                |
+-------------------------------------------------------------------+
               Local      Incoming     Outgoing   
    Node    ENQ/CVT/DEQ  ENQ/CVT/DEQ  ENQ/CVT/DEQ
  --------  -----------  -----------  -----------  
  MELODY      3/  3/  3    2/  3/  2    1/  2/  1 
  PISCES      7/  8/  7   16/ 15/ 16    0/  1/  0 
  GUMDRP     20/ 33/ 20    0/  0/  0   15/ 11/ 15 
  FORNOW      0/  0/  0    0/  0/  0    0/  1/  0
 I once tried to find out the actual traffic from any node to other nodes.
 For instance, Melody has two incoming ENQs and 1 outgoing ENQs. Where are
 they coming from and where is it going to? I tried to generalize this for
 N nodes. I did not spend too much time on it. I gave up thinking that not
 enough information is available to solve the problem. Did any one solve this
 problem?
Swamy
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 840.1 | but I digress | ZFC::DERAMO | I voted on Super Tuesday! | Tue Mar 08 1988 19:53 | 9 | 
|     That reminds me of a [a) similar b) totally unrelated] problem.
    The NFL standings were in the newspaper two weeks into the
    season, with the won-loss and points for-against totals for
    each team.  I also had a schedule so I knew who had played whom.
    
    I never did figure out if this was enough information to derive
    the score of each game.
    
    Dan
 | |||||
| 840.2 | CLT::GILBERT | Wed Mar 09 1988 09:30 | 8 | ||
|     Suppose we have 3 nodes: A, B, and C, with i arcs between A and B,
    j arcs between A and C, and k arcs between B and C.  We are given
    i+j (arity of A), i+k (arity of B), and j+k (arity of C), and want
    to determine i, j, and k.  That gives 3 equations in 3 unknowns.
    Suppose we have 4 nodes.  We get 4 equations in 6 unknowns.
    Suppose we have n nodes.  We get n equations in n(n-1)/2 unknowns.
 | |||||
| 840.3 | ZFC::DERAMO | Think of it as evolution in action. | Wed Mar 09 1988 09:59 | 4 | |
|     But the fact that the solutions are limited to nonnegative integers
    gives more constraints than just "n equations in n(n-1)/2 unknowns."
    
    So maybe some n=4 cases can be solved, too. (-:
 | |||||
| 840.4 | TLE::BRETT | Wed Mar 09 1988 13:39 | 17 | ||
|     Consider the trivial case,
    
              outgoing                  incoming
    
    		A			  C
    
    		B                         D
                                           
    
    Now, if A and B each have one out-going link, and C and D each have
    two incoming links, there is (obviously) no way of determining
    whether (AC, BD) or (AD, BC) was the actual pattern.
    
    Since you can't solve the simple case...
    
    
    /Bevin
 | |||||