Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Junior Member
 
Posts: 1
Default Solver Binary Contraints problem

I'm using Solver to determine which combination of numbers in a column result in the given total.

For example, the data is in E1:E42 and I've set J1:J42 to 0.
$J$43 = SUMPRODUCT(E1:E2*J1:J42)
$J$44 = the value I'm searching for
$J$45 = J44-J43 and is the Solver Target Cell
I'm Solving to 0 by changing cells $J$1:$J$42
Subject to the Constraints: $J$1:$J$42=binary

When I set the constraint to binary, instead of setting the changeable cell from 0 to 1, it sets the cells to a large decimal between 0 and 1.
I've also tried adding the integer constrait to no avail.
Is there any way to force Solver to limit the values of the changeable cells to either a 0 or 1?
Thanks.
  #2   Report Post  
Posted to microsoft.public.excel.worksheet.functions
external usenet poster
 
Posts: 1,071
Default Solver Binary Contraints problem

The technique that Solver uses (Branch and Bound) is a standard one from the
field of optimization. Essentially, it uses real numbers (i.e., ignores the
binary/integer constraint) except at certain points in the process when it
brings them back into play.

So, if your optimization fails before completion (no feasible solution,
exceeds allowed iterations / time, etc.), some of the integer values may be
non-integer.

Also, Solver allows one to control the accuracy of the final solution
through 3 variables. In the Solver dialog box, click the Options button.
In the next dialog box, click the Help button and read up on Precision,
Tolerance, and Convergence.

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article ,
says...

I'm using Solver to determine which combination of numbers in a column
result in the given total.

For example, the data is in E1:E42 and I've set J1:J42 to 0.
$J$43 = SUMPRODUCT(E1:E2*J1:J42)
$J$44 = the value I'm searching for
$J$45 = J44-J43 and is the Solver Target Cell
I'm Solving to 0 by changing cells $J$1:$J$42
Subject to the Constraints: $J$1:$J$42=binary

When I set the constraint to binary, instead of setting the changeable
cell from 0 to 1, it sets the cells to a large decimal between 0 and
1.
I've also tried adding the integer constrait to no avail.
Is there any way to force Solver to limit the values of the changeable
cells to either a 0 or 1?
Thanks.




--
Rick Kaullen

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solver does not work from Macros mjd918 Setting up and Configuration of Excel 1 January 6th 06 04:15 PM
solver problem Donna Excel Worksheet Functions 1 December 4th 05 05:08 PM
Excel Solver Issue nakedbamboo Excel Discussion (Misc queries) 5 November 14th 05 01:26 AM
Trouble with Solver Wanderingspirit99 Excel Discussion (Misc queries) 0 September 12th 05 03:50 PM
Solver problem nj125 Excel Discussion (Misc queries) 2 May 19th 05 05:19 AM


All times are GMT +1. The time now is 03:19 AM.

Powered by vBulletin® Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 ExcelBanter.
The comments are property of their posters.
 

About Us

"It's about Microsoft Excel"