p2p.wrox.com Forums

p2p.wrox.com Forums (http://p2p.wrox.com/index.php)
-   Excel VBA (http://p2p.wrox.com/forumdisplay.php?f=79)
-   -   Linear programming problem (http://p2p.wrox.com/showthread.php?t=32658)

milk_vanilla August 19th, 2005 03:07 AM

Linear programming problem
 
hi there,
i have prob for my final assignment,that i should build a program that could calculate minimum optimizing for linear program problem.i thought that u guys, known this case.
what i want to ask is, should i build this program using VBA, of course!, Or we can build in VB.net or something?
btw i never use vba in my life =), but one thing i know, sometimes people tell that vba is used like an Excel problem. is it true? can someone tell wider in different perspection. thx


mjppaba August 19th, 2005 04:00 AM

Sounds like an interesting assignment.

In principle, the worksheet is merely a User interface of the VBA code behind the scenes, you are just passing values from the front end to the backend. What I have done of Linear programming in the past has only been fairly basic compared to your requirements, but excel can handle these both in the front end and through the use of User Defined Functions (UDF) combined with VBA programming. UDF's are by far and away more versatile, however the can be a bit cranky occasionally. For instance you could write a UDF that calculates the result of a variant of the Chi squared calculation, there is already a CHITEST calc but you may want a different statistical calculation. As far as I am aware this is not a standard function in Excel but because you are creating it, it can work.

To create a UDF is fairly easy, there's plenty of manuals available on UDFs and here on the boards we are always ready to help in any way we can, only don't ask us to do you work, make your questions quite specific.

Hope this is helpful.

Matt

milk_vanilla August 21st, 2005 09:27 AM

i'm never study about vba, is it same like vbscript? or language that we use in .net?if there's any differences, can u guys share bout these knowledge =). btw, what is UDF, is it something that we build ourself function to run through it?
i know about .net language, can it solve my problem? i mean, can i use .net for build my program. and what i need to know for sure is, can .net solve any equation problem or we should solve this equation manually? this is the most important stuff for linear problem. thx


jjd August 23rd, 2005 09:08 AM

Do you have to program the LP solving process or do you just need to solve an LP? If you just need a solution, use the built-in solver. If you have to program the process (e.g. simplex,dual,interior point, etc), you might want to use something Matlab that supports more matrix operations. If you have to do it in VBA/.Net, you will have your work cut out for you, but of course it can be done.


milk_vanilla August 23rd, 2005 11:40 PM

no, i have to made a program to solve a problem with .net/vb
anybody 've built it?
i've got problem with the equation, how should we do, when we need to solve any equation in .net?
thx


jjd August 25th, 2005 09:06 AM

I really think you need to look at some basic material to familiarize yourself with LP. Try a book like [u]Introduction to Linear Optimization</u>. Then you can really think about how you will implement your solution. You can't just sit down and program a linear optimization program without some understanding of HOW to solve an LP problem.



All times are GMT -4. The time now is 02:17 PM.

Powered by vBulletin®
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
© 2013 John Wiley & Sons, Inc.