Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Need help in vb

  1. May 7, 2004 #1
    i wanna make a linear program which has such this conditional:
    if the inputs have 2 variables (ex. x & y) and make equations (ex. 2x + 3y <= 23, 5x + y <= 12) then both equation will shown in graphic.
    but if the inputs have more than 2 variables (ex. x, y & z) and have some equations then the solution shown in table.
    both programs are optimization case (minimization or maximization).
    can any one help me in making the source codes in vb and/or the algorithms? i really need it, pls!!! if u have the info feel free to send me an email to fida_nich@hotmail.com
  2. jcsd
  3. Jun 30, 2004 #2
    This is very tedious job to solve the equation in the generic programming language
    So please use the vb script embedded in the visual basic program to solve the equation

    Systax :

    [result = ]Eval(expression)
    Arguments result Optional. Variable to which return value assignment is made. If result is not specified, consider using the Execute statement instead.
    expression Required. String containing any legal VBScript expression.

  4. Jun 30, 2004 #3

    In VBScript, x = y can be interpreted two ways. The first is as an assignment statement, where the value of y is assigned to x. The second interpretation is as an expression that tests if x and y have the same value. If they do, result is True; if they are not, result is False. The Eval method always uses the second interpretation, whereas the Execute statement always uses the first.

    Note In Microsoft® JScript™, no confusion exists between assignment and comparison, because the assignment operator (=) is different from the comparison operator (==).
    The following example illustrates the use of the Eval function:

    Sub GuessANumber
    Dim Guess, RndNum
    RndNum = Int((100) * Rnd(1) + 1)
    Guess = CInt(InputBox("Enter your guess:",,0))
    If Eval("Guess = RndNum") Then
    MsgBox "Congratulations! You guessed it!"
    Exit Sub
    Guess = CInt(InputBox("Sorry! Try again.",,0))
    End If
    Loop Until Guess = 0
    End Sub
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook