Getting the relationship between two numbers

Mavix · 01-29-2008, 11:22 AM

I have two numbers, that I have got from angle, using Cos and Sin. If I add the numbers together, they generally range from about 0.6 to about 1.6. How can I write a method that makes the numbers larger or smaller, so that they add up to a given number, for example 1, while still holding their relationship to each other?

Elysia · 01-29-2008, 11:32 AM

Huh? I don't understand what you mean. Especially about "while still holding their relationship to each other".
And how to make a number larger or smaller? I'm guessing it's related to the above somehow.

Mavix · 01-29-2008, 11:37 AM

Lets say, for example, the two numbers, X and Y, are 0.6 and 0.9. If added together they equal 1.5. Now how would I go about lowering both numbers, while keeping their ratio, till they are both equal to 1, or any given number?

Elysia · 01-29-2008, 11:40 AM

I see. So an equation, huh?
Oops. Bad solution.

Llam4 · 01-29-2008, 12:19 PM

Quote:

Originally Posted by Elysia

I see. So an equation, huh?
One way would be to do this:

Code:

float x = 0.6f;
float y = 0.9f;
float total = x + y;
float rest = total - 1.0f;
float subtract = rest / 2;
x -= subtract;
y -= sibtract;

Wouldn't it?

No, that would take 0.25 from 0.6 and 0.25 from 0.9, which is obviously not a relative result.

Code:

float x = 0.6f;
float y = 0.9f;

float x2 = x / (x + y);
float y2 = y / (x + y);

Dino · 01-29-2008, 12:21 PM

Quote:

Originally Posted by Elysia

Wouldn't it?

I don't think so.

You want ratios.

.6 + .9 = 1.5, and you want them to add up to 1.0.

Read another way, you have .60 and .90 and they add up to 1.50. If we multiply by 100, you have

60% + 90% = 150%, but you want them to add up to 100%.

So, figure out what % .6 is of 1.5, and that is 40%.

.6 / 1.5 = 40.

Checking our math,

.9 / 1.5 = 60.

40% + 60% = 100%, so the answer is .4 and .6.

Todd

Elysia · 01-29-2008, 12:41 PM

Oops, think I missed the "keep ratios" words there.

oogabooga · 01-30-2008, 09:25 AM

I don't know C#, but in general you want something like this (where limit in your example would be 1.0).

Code:

    convert = limit / (x + y);
    x *= convert;
    y *= convert;

Mavix · 01-30-2008, 01:05 PM

Quote:

Originally Posted by oogabooga

I don't know C#, but in general you want something like this (where limit in your example would be 1.0).

Code:

    convert = limit / (x + y);
    x *= convert;
    y *= convert;

Thanks, that worked. It took me a while to figure out that I need absolute values, but I got it working. Once again, thanks!

01-29-2008, 11:22 AM	#1
Mavix Registered User Join Date: Sep 2006 Posts: 98	Getting the relationship between two numbers I have two numbers, that I have got from angle, using Cos and Sin. If I add the numbers together, they generally range from about 0.6 to about 1.6. How can I write a method that makes the numbers larger or smaller, so that they add up to a given number, for example 1, while still holding their relationship to each other?
Mavix is offline

01-29-2008, 11:37 AM	#3
Mavix Registered User Join Date: Sep 2006 Posts: 98	Lets say, for example, the two numbers, X and Y, are 0.6 and 0.9. If added together they equal 1.5. Now how would I go about lowering both numbers, while keeping their ratio, till they are both equal to 1, or any given number?
Mavix is offline

01-30-2008, 09:25 AM	#8
oogabooga Registered User Join Date: Jan 2008 Posts: 64	I don't know C#, but in general you want something like this (where limit in your example would be 1.0). Code: convert = limit / (x + y); x = convert; y = convert;
oogabooga is offline

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