Questions

[Joshua Lepinski]

so I remember us refereing to sets N and B in class but I can't seem to find my notes from that day. I know when we pick a c it gets transfered from one set to another and when we pivot we set one of them back to the one it was originally in. I'm not very good at interpreting these types of documents but I also am trying to figure out what I do with Delta sub i after I have it. if you have a negative number in it's place you know the whole problem is unbounded right? not just that value? I think I can get it all done if I can just figure out the starting values of N and B and the points at which they change. I seem to remember that one of them is the things that we assume in our equation evaluate to zero.

[Joshua Lepinski]

In the notes it also indicates that delta sub i is the smallest one so is the reason for the for loop to find the smallest one?

[Brad Spendlove]

So, N starts as the set of the "real" variables (the ones for copper, gold, etc), and B is full of the "slack" variables (Just store their indices). The contents of N and B only change during the pivot step when l leaves B and gets added to N and e leaves N and gets added to B.

Hope that helps

On Thu, Jul 26, 2012 at 4:53 PM, Joshua Lepinski <joshual...@gmail.com> wrote:

In the notes it also indicates that delta sub i is the smallest one so is the reason for the for loop to find the smallest one?

--
You received this message because you are subscribed to the Google Groups "BYU CS 312 Summer 2012" group.
To post to this group, send email to byu-cs-3...@googlegroups.com.
To unsubscribe from this group, send email to byu-cs-312-sum...@googlegroups.com.

To view this discussion on the web visit https://groups.google.com/d/msg/byu-cs-312-summer/-/ZD9TnR-XSssJ.

For more options, visit https://groups.google.com/groups/opt_out.
 
 

[Clint]

From what I understand, Delta_i is for finding your leaving variable.  You find the minimum of the delta_i for each i in B, and your leaving variable is the index i of the minimum delta.  I think the problem is only unbounded if every single a_i,e value is less than or equal to 0

[Christopher Tensmeyer]

That is correct.  The loop is to find the tightest constrainst for that variable as measured by delta.  However, if there exists a variable with a positive coefficient in the objective function that has negative deltas for all I, then there is no constraint that bounds it.  Therefore, its value can be increased arbitrarily.  Then we say the problem itself is unbounded.

Chris

[Joshua Lepinski]

So coming down to the end of the day my implementation is giving me
v=35473.2   c[ 0 ] g [ 84 ] s[ 0 ] p[ 0 ]


I know the result is not correct since the online one gives me

Optimal Solution: p = 54592; w = 0, x = 0, y = 0, z = 64

my  matrices are looking like this as I enter the pivot phase

I know I should be able to pull up what we did in class and figure it out what my problem is but I just can't remember how to do it.

Do you think I should turn it in now and lose out on those points or should I come talk to someone on Monday and try to get things figured out then?
There seem to be a lot riding on the right answer for this lab, and I'm just kind of burnt out right now.

I think I'm going to come in early on Monday and ask for help going over the math again.

Start

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0.1 ] [ 0.5 ] [ 0.333 ] [ 1 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 30 ] [ 15 ] [ 19 ] [ 12 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 1000 ] [ 6000 ] [ 4100 ] [ 9100 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 50 ] [ 20 ] [ 21 ] [ 10 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 4 ] [ 6 ] [ 19 ] [ 30 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]



c: [ 10.2 ] [ 422.3 ] [ 6.91 ] [ 853 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

N: [ 0 ] [ 1 ] [ 2 ]

L: [ 8 ]

E: [ 3 ]

B: [ 4 ] [ 5 ] [ 6 ] [ 7 ]


b: [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 2000 ] [ 1000 ] [ 1000000 ] [ 640 ]


Round 2
[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]

[ 0.133333333333333 ] [ 0.2 ] [ 0.633333333333333 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0.0333333333333333 ]

[ -0.0333333333333333 ] [ 0.3 ] [ -0.300333333333333 ] [ 1 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ -0.0333333333333333 ]

[ 28.4 ] [ 12.6 ] [ 11.4 ] [ 12 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ -0.4 ]

[ -213.333333333333 ] [ 4180 ] [ -1663.33333333333 ] [ 9100 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ -303.333333333333 ]

[ 48.6666666666667 ] [ 18 ] [ 14.6666666666667 ] [ 10 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ -0.333333333333333 ]

[ 4 ] [ 6 ] [ 19 ] [ 30 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]


c: [ -103.533333333333 ] [ 251.7 ] [ -533.323333333333 ] [ 853 ] [ 0 ] [ 0 ] [ 0 ] [ 0 ]


N: [ 0 ] [ 2 ] [ 8 ]

L: [ 3 ]

E: [ 1 ]

B: [ 4 ] [ 5 ] [ 6 ] [ 7 ]

b: [ 0 ] [ 0 ] [ 0 ] [ 16.8 ] [ 1983.2 ] [ 798.4 ] [ 847120 ] [ 472 ]