How to Represent a Data Table (Matrix)

[litlmike]

I feel kinda dumb asking this because I have been working with 2-dimensional arrays for a while now, but I have always just been grabbing data from one location and pasting it in another. And it is always just a loop of getting data 1 piece at a time.

But now, I want to create the array, and then use it based upon user input. So the question is, How to Represent a Data Table (Matrix)? Or, how do I create a 2-dimensional array? And in a way that if the user enters the data that I can just grab that 1 element?

For Example:

Here is a table, that I want to create.

http://kirstyne.files.wordpress.com/2007/0...s_bmi_chart.gif

The user should be able to put in data, like 6'0" ($feet = 6 ; $inch = 0) and weight like 200 lbs and have the number 27 returned giving them their BMI. The only way that I know to create the array, is to do this, but that seems rudimentary and there should be a better way. This is a small chart, what if were 1,000 times this size, it seems like someone would have a better method than this:

$aBMI[0][0] = 29
$aBMI[1][0] = 27
$aBMI[2][0] =  25

The chart isn't perfectly linear and so making a loop doesn't seem to make sense to me. How do I make this table? And how do I grab data from it, based upon the users input?

Thanks.

Edited April 18, 2008 by litlmike

[weaponx]

Do you even need the chart? BMI is weight / height^2

[litlmike]

Do you even need the chart? BMI is weight / height^2

Yea, I guess you are right about that, but for the sake of learning how to do this in the event there wasn't a formula is this easliy done? I guess I imagine it could just be an enormous table with the result just being True/False depending on the variables. I thought about it, and I just couldn't figure out how to program something like that.

Thanks

[PsaltyDS]

The rows and columns in that table are height and weight. You have to assign some standard values for $aBMI[$h][$w], like $h is height in inches divided by 2, and $w is weight in pounds divided by 10. So $aBMI[30][21] would be the entry for 60" tall and 210lbs. If you have the formula to convert height/weight to BMI, then you could loop it through the array and fill in the values easily.

[PsaltyDS]

Do you even need the chart? BMI is weight / height^2

Well, the table he linked to was in english measure. So it would be weight(lbs.) * 703 / height(in.)^2.

The real question is: If you have the formula, why bother with a table? Given $h and $w just do the math and get the BMI. Why bother with an array at all?

Edited April 18, 2008 by PsaltyDS

[weaponx]

expandcollapse popup

#include <GUIConstants.au3>
#include <StaticConstants.au3>

Const $boardColumns = 14
Const $boardRows = 14
Const $cellSize = 20
Const $cellSpacing = 2
Const $boardMargin = 40

Const $startHeight = 54
Const $startWeight = 120

;Array to store all label handles
Dim $boardArray[$boardRows][$boardColumns][2]

;Create GUI window
GUICreate("BMI", (($cellSize+$cellSpacing)*$boardColumns) + ($boardMargin*2), (($cellSize+$cellSpacing)*$boardRows) + ($boardMargin*2))  ; will create a dialog box that when displayed is centered

$currentHeight = $startHeight
For $Y = 0 to $boardRows - 1

    ;Reset current weight at beginning of each row
    $currentWeight = $startWeight
    
    For $X = 0 to $boardColumns - 1
        
        ;Draw weight headings
        If $Y = 0 Then
            GuiCtrlCreateLabel($currentWeight,($X*($cellSize +$cellSpacing)) + $boardMargin, $boardMargin - 15, $cellSize, $cellSize, $SS_CENTER)
        EndIf
        
        ;Draw height headings
        If $X = 0 Then
            GuiCtrlCreateLabel(InchesToFeet($currentHeight),7, ($Y*($cellSize+$cellSpacing)) + $boardMargin, 30, $cellSize, $SS_RIGHT)
        EndIf
        
        ;Get BMI
        $currentBMI = BMI($currentHeight, $currentWeight)
        
        ;Draw label
        $boardArray[$Y][$X][0] = GuiCtrlCreateLabel($currentBMI,($X*($cellSize +$cellSpacing)) + $boardMargin, ($Y*($cellSize+$cellSpacing)) + $boardMargin, $cellSize, $cellSize, $SS_CENTER )
        GUICtrlSetFont(-1, 9, 600) ;Bold
        GUICtrlSetColor(-1,0x44494a) ;Dark grey
        
        ;Identify severity of BMI using color
        Switch $currentBMI
            Case 1 To 18
                GUICtrlSetBkColor (-1, 0xa9d7d9);Blue
            Case 19 To 24
                GUICtrlSetBkColor (-1, 0xf37042);Red
            Case 25 To 29
                GUICtrlSetBkColor (-1, 0x97c05b);Green
            Case Else
                GUICtrlSetBkColor (-1, 0xf5e77d);Yellow
        EndSwitch
        
        ;Increment 10 pounds at a time
        $currentWeight += 10
    Next
    
    ;Increment 2 inches at a time
    $currentHeight += 2
Next

GUISetState (@SW_SHOW)       ; will display an empty dialog box

; Run the GUI until the dialog is closed
While 1
    $msg = GUIGetMsg()
    
    If $msg = $GUI_EVENT_CLOSE Then ExitLoop
Wend

;Return BMI given height (in inches) and weight (in pounds)
Func BMI($height, $weight)
    Return Floor(($weight * 703) / ($height^2))
EndFunc

;Convert inches to feet/inches string
Func InchesToFeet($inches)  
    $feet = Int($inches / 12)
    $remain = Mod($inches, 12)
    Return $feet & "' " & $remain & '"'
EndFunc

Edited November 14, 2008 by weaponx