Decimal hell.

[Vapyrical_Curse]

I'm very frustrated cos what I thought would a simple task turned out to be hellish.

I'm trying to make a simple function which finds percentages. I am doing this by having the user input a number on a box and the other number on another box.. EG: What percentage is 50 of 100? The result should be a simple 50, but it returns 0. I already tried changing 100 to 100.0 and it just doesn't work, some numbers just won't come out and others will give erratic results. This is my formula:

First Box / Second Box * 100.0

As far as I know I am doing nothing wrong. Thank you for yer help.

[Popcorn]

Try:
First box / (second Box * 100.0)

This will make the second number into a float before the calculation.

Now, it probably does this:

Integer / Integer = Integer
Integer * Float = Float

...which as you see, converts the result into a float AFTER the first calculation.

[Vapyrical_Curse]

Try:
First box / (second Box * 100.0)

This will make the second number into a float before the calculation.

Now, it probably does this:

Integer / Integer = Integer
Integer * Float = Float

...which as you see, converts the result into a float AFTER the first calculation.

Tried and it partially fixes the problem. Now it does show decimals, but let's say we use the easy what % 50 is of 100, it will only show 0.005 as if it was dividing by 100 instead of multiplying.

:crazy:


EDIT: Seems after doing that I had to multiply it by 10000 for it to work... I did not know MMF worked like this? Why is that?

EDIT 2: Darn! Sometimes it gives wrong percentages now... I did randomly try to do what percentage 60 was of 2.99999 and it said 3000 when when I do it on a number of other ways it says 2000.006666688889. I'm kind of really confused about this...

[Dynasoft]

The correct formula is: (First box * 100.0) / second Box. Always do multiplies first if you can, it's more accurate.

Also popcorn had the multiply grouped under the divide, so it effectively became a divide by 100...

[Yves]

1. You should do : (First box * 100.0) / second Box

EDIT: ah, Dynasoft was faster

2. It's due to the way computers store floating point values. Already discussed here.

[Popcorn]

Haha, it was early in the morning
Sorry for the confusion!

[Vapyrical_Curse]

Thanks for all the help guys, really. By doing that it works just fine, but still gives some erratic values. Like that 60 of 2.99999
it returns 3000% which I know is very incorrect given the fact that, any other method returns 2000.006666688889%. Why is this? Any way to correct this?

[DavidN]

It definitely sounds like something else is wrong - maths just isn't this... erratic! I would check any other events that could possibly be affecting any of those counters or values...

[Dynasoft]

You'd get 60 of 2.99999 = 3000% if you were rounding down the 2.99999 to 2. You're not using "value of editbox" are you? Use "Val()" on the "text of editbox" instead.

[Anders]

Yes the expression of the edit box to get the nummeric value only returns integers. As Dynasoft sais you have to use Val() on the text of the edit object.