The LA Fox Developer

A Newsletter for FoxPro Application Developers in Southern California

Visit our WebSite at: http://www.mesllc.com/lafox.html

October 1999

Scheduling Concepts and the

Database Manager

By Joe Pecukonis, Rocky Mountain Fox User Group

Most organizations have scheduling demands. These schedul-

ing problems fall into the area of operations mathematics called

Integer Programming (IP) or Discrete Programming in general

mathematics terms. It is called Integer or Discrete Programming

because each step is a go or no-go issue rather than an

analytical solution. Below I will cover three common types of

scheduling problems using IP with database solutions. Once

you are familiar with these basic concepts, you can use them or

a combination of them to solve those really difficult scheduling

problems.

The “Container Problem”

A common IP scheduling problem is called the “container

problem”. It is assumed that there is a container of a fixed size

and items of variable sizes that need to go into the container.

This problem is encountered whenever a railroad car, plane,

truck, or shipping box is packed or loaded. One example of this

problem is the need to copy all of the files in a subdirectory of a

hard drive onto a group of 3.5” floppies.

A solution to this problem would be to create a database table

of all the files on the subdirectory along with the size of each

file. Then, index by size and go to the bottom. Check to see if

the largest file will even fit on the floppy. If it won’t, tell the user.

If it will fit, then copy that one file to a floppy. Now subtract the

file size from the available size that is left on the floppy. Now,

that you know the available size that is left on the floppy, locate

a file that is the same size or smaller. Now, copy that one to the

floppy and keep repeating until the size left on the floppy is less

than the smallest file in the database table. Then, start with a

newfloppy and repeat.

At LA Fox

October 18, 1999, 7:30 PM, Mike Vincent. Since presenting

his introductory session on DBI Tech’s ActiveX Controls, Mike

has discovered several cool things about this tool. (Please see

“About October’s Meeting”, page 9.) ActiveX controls can

significantly add to the functionality and visual iinterface of your

VFP applications. As you may know, there is a learning curve

and some controls work better than others with VFP. He’ll

provide an overview of controls from severai sources, then dflii

into details of implementing some that he is using in his own

projects. He’ll also share some experiences on the in and outs

of managing ActiveX controls in both development and end-user

environments. Don’t miss this one...

November 15, 1999, 7:30 PM, Twila Miller. Twila always

provides us with outstanding presentations. This one promises

to be no different.. .“OLE Automation with MS Word and Excel”.

If she has time, she’ll also be covering some MAPI issues as

well.

December 20, 1999, 7:30 PM, The Annual LA Fox Christ-

mas Party. It’s that time of the year again. Come join us for

merriment, good times, LA Fox fellowship, and tasty treats.

And what would the Christmas party be without The White

Elephant Gift Exchange? So come prepared for a good time.

Elsewhere

May 14-17, 2000, VFP DevCon 2000, New Orleans

(Con't page 2)

Out and About

by Barry R. Lee

The October meeting of LA Fox will be held

on Oct. 18, 1999, at 7:30 PM at our new meet-

ing place (NCR, 100 N. Sepulveda Blvd., El

Segundo, CA). For details on how to get

there, see the map on the back page.

(Con't page 7)

In this issue

Removing Obstacles

Inter-Object Communications

FoxPro Q&A

Page 2

Page 3

Page 6

....and much more!