[moonmonkey]

What's the formula for converting a negative to a positive.

Eg how to I convert -10 to 10?

I know its something stupidly simple but I had a beer for lunch and its wiped my memory.

Thanks.

[Albert Pujols]

+20

[moonmonkey]

Originally Posted by Albert Pujols

+20

Not really what I was after, it had to work for all numbers, not just -10

[Albert Pujols]

um, I don't know what you want...but

x+(-3.141)=3.141 Just add x to the negative number you have and you have your positive?

My bad if I'm wrong, I have to "wake up" for school in an hour.

[f1000]

Absolute value.

[Albert Pujols]

d'oh

[f1000]

Originally Posted by Albert Pujols

um, I don't know what you want...but

x+(-3.141)=3.141 Just add x to the negative number you have and you have your positive?.

What the?

[Albert Pujols]

Originally Posted by f1000

What the?

haha..it made sense to me at the time

x-10=10
x=20
-10+20=10



|-10|=10

[moonmonkey]

I figured it out (please don't laugh)

Assuming x is a negative number

x=(x-x-x)

[Albert Pujols]

oh...math is gay. What has math done for me..nothing.

edit: that formula isn't exactly right but whatever.

[Big Mac]

Haha, I thought this thread would contain up-beat, cheery advice and other life-affirming platitudes.

[Millennium]

Absolute value. Most programming languages and spreadsheets have an abs() function for this purpose.

[Millennium]

The standard C libraries have this function, but here's a quick implementation for integers:

Code:
int abs(int number){
    if (number <= 0) {
        return number * -1;
        }
    else {
        return number;
        }
    }

[Eriamjh]

Times -1

[bstone]

Omg! This Belongs In The Political Forums!!!!!

[ghporter]

The "mathematical formula" for absolue value is almost identical to the code Millenium posted...or actually the code is almost identical to the formula.

Anyway, absolute value is "displacement from zero," so it MUST be positive. That yields the following:

If X < 0 then |X| = X * -1. Otherwise |X| = X.

It really is that simple.

P.S., the symbol for absolute value is "|X|" We started using it here without pointing that out.

[saddino]

In the old C days, I believe abs() used to be implemented as a macro, though such an optimization is probably not that important anymore:

#define abs(a) (((a) < 0) ? -(a) : (a))

[RGB]

Originally Posted by Eriamjh

Times -1

Winner.

[mitchell_pgh]

Originally Posted by Eriamjh

Times -1

I was waiting for that... hmmm...

[phantomdragonz]

Originally Posted by Eriamjh

Times -1

That is the simplest way to do it, but it also works the other way too...

Zach

[Millennium]

Originally Posted by Eriamjh

Times -1

Not quite; you only multiply by -1 if the number is already negative. If it's positive, you just leave the number as it is.

[mitchell_pgh]

Originally Posted by Millennium

Not quite; you only multiply by -1 if the number is already negative. If it's positive, you just leave the number as it is.

but that wasn't the question...

What's the formula for converting a negative to a positive.

[sideus]

+1.

[DeathMan]

This thread cracks me up. I didn't know there was some magical number for converting a negative number to its positive self!

y = -x

Was this really a serious question?

[Xeo]

Took long enough to come to -1. Geez. But yeah, I was thinking "well you can only -1 it if it's less than 0" but Mill posted an abs() function so it's all good.