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Index › Programming Questions & Help › Syntax Questions › natural E constant
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natural E constant? (Read 2516 times)
Ricard
natural E constant?
Apr 21st, 2005, 11:40am  
Is there any E constant, or an exp() function?
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K. Damkjer
Re: natural E constant?
Reply #1 - Apr 21st, 2005, 3:40pm  
Since Processing sits on top of Java, you can always snag these from Math, but you'll have to remember to cast them to float for most Processing purposes (I believe they're double by default).

For example:
Code:
float E = (float) Math.E;


I also tried the following, but I was informed (by the compiler) that exp already exists as a final method in PApplet. Oops.  Looks like we surfaced an undocumented method.

Code:

float exp(float a) {
  return (float) Math.exp(a);
}


Perhaps we need to throw that one in with the rest of the mathematics docs.
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Ricard
Re: natural E constant?
Reply #2 - Apr 21st, 2005, 4:02pm  
Thanks!

Don't you think it would be a good idea to have the E constant the same way as HALF_PI, PI and TWO_PI, is there a reason for not having it that way?

And thanks for pointing out about the hidden exp() function.  I think it would be a good idea to document it as you say, in the complete reference.
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TomC
Re: natural E constant?
Reply #3 - Apr 21st, 2005, 4:45pm  
E is a tricky one.  You're unlikely to want a variable called PI which isn't 3.141..., but E isn't so safe.  If you need E, try this:

Code:

float E = exp(1);

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