Need math help

[GMK]

Let's say I have a font size at any given pixels.  In a certain program, the auto-sized box given this font size has a height that can be calculated using the following formula:

Global $iPixels = 100
Global $iBoxHeight = $iPixels + Int($iPixels / 5) + 14 ; $iBoxHeight = 134

I can't for the life of me figure out how to find the pixels, given the height, or if it's even possible.

Any help would be greatly appreciated.  Thanks!

[jchd]

Can you test this:

$iPixels = Round(($iBoxHeight - 14) * 5 / 6)

 

[GMK]

It's close, but not exact.

#include <Array.au3>
Global Enum $ePx, $eBoxHeight, $ePxCalculated
Global $aArray[100][3]
For $iRow = 0 To 99
    $aArray[$iRow][$ePx] = $iRow + 1
    $aArray[$iRow][$eBoxHeight] = $aArray[$iRow][$ePx] + Int($aArray[$iRow][$ePx] / 5) + 14
    $aArray[$iRow][$ePxCalculated] = Round(($aArray[$iRow][$eBoxHeight] + 1 - 14) * 5 / 6)
Next
_ArrayDisplay($aArray)

 

[GMK]

Thank you, by the way.

[GMK]

I found some help here.

$iPixels = Ceiling(($iBoxHeight * 5 - 70) / 6)

Thanks, @jchd!

[jchd]

Yup, I wasn't sure about the rounding direction. Both equation yield the same result before rounding (ceil vs. floor).

[aleph01]

If my algebra still works,

$iBoxHeight = $iPixels + Int($iPixels / 5) + 14

I translate to

H = P + (P/5) + 14
H-14 = P + (P/5)
H-14 = 1.2P
(H-14)/ 1.2 = P

or in your variables, = ($iHeight - 14) / 1.2 = $iPixels

Substituting the numbers, 
(134-14)/1.2 = $iPixels  ; (Height-14) / 1.2 = Pixels
120/1.2 = $iPixels
100 = $iPixels

Use  (Height-14) / 1.2 = Pixels

That's the math.  You can work on rounding to whole numbers if necessary.  Hope you can follow that.  Hope I didn't make a mistake; it's been a long time., but I think that's right.

Good luck,

_aleph_

Edited October 14, 2016 by aleph01
spelling correction