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Index › Programming Questions & Help › Syntax Questions › Partial RandomSeed()
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Partial RandomSeed() (Read 526 times)
Tor
Partial RandomSeed()
Dec 10th, 2007, 9:52am  
Hi,

Is there a way to use randomSeed only on specific parts of program? Or rather could I introduce some sporadic instances of "pure randomness" and still use randomSeed for the rest?

Thanx
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JohnG
Re: Partial RandomSeed()
Reply #1 - Dec 10th, 2007, 10:47am  
You can create separate Random objects to use in specific areas, and give them set seeds: http://java.sun.com/j2se/1.4.2/docs/api/java/util/Random.html
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Tor
Re: Partial RandomSeed()
Reply #2 - Dec 10th, 2007, 10:46pm  
Thanks John, that looks like just what I need. Sadly though my understanding of pure Java is not good enough to make out how to go about it from reading the javadoc. If anybody could give me a hint on how this would look in processing code I would be very grateful.
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JohnG
Re: Partial RandomSeed()
Reply #3 - Dec 10th, 2007, 11:37pm  
It would look something like:

Code:
Random myRandom(123456);
int a=myRandom.nextInt(1000); // a random number from 0-1000

Random myOtherRandom(123456);
int b=myOtherRandom.nextInt(1000); // b==a

int c=random(1000); // a completely unrelated number, since this uses processing' built-in random source.
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Tor
Re: Partial RandomSeed()
Reply #4 - Dec 11th, 2007, 9:34pm  
Thanks again John, that will be really helpful Smiley
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kklex05
Re: Partial RandomSeed()
Reply #5 - Jan 23rd, 2008, 7:26pm  
Hey,

I think I have the same problem like Tor.
I need for only 2 variables a random with randomSeed. After this I need a variable with changes randomly. There are all in a for-loop, like this:

draw(){
for (0 to 2){
 float a = random(0,1); //this I need randomly changes
 float x = random(1,5); //should be the same each time
 float y = random(1,5); //should be the same each time
}
}

The code from JohnG I can't handle. Do I need a extra class "Random" to get this problem solved???
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JohnG
Re: Partial RandomSeed()
Reply #6 - Jan 23rd, 2008, 8:32pm  
Your problem can be solved much easier:

Code:
float x;
float y;

void setup()
{
  //normal setup
  x=random(1.5);
  y=random(1.5);
}

void draw()
{
//stuff
  float a=random(0.1);
  //stuff that uses x y and a
//more stuff...
}
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