Java math expression parser that can take complex numbers as a variable?

Question

I am writing a program in Processing that transforms complex numbers. However, I want to have a method of taking an input string and calculating the transformation using a compl

Answer 1

As mentioned by PhiLo, you can use generics. Try this Processing sketch:

import java.util.*;
java.util.List<String> list = Arrays.asList("a", "b", "c");
textFont(loadFont("UMingCN-30.vlw"));
for(int i = 0; i < list.size(); i++) {
  text(list.get(i), 5, int(i*30)+30);
}

And there's a non commercial version of JEP available (GPL). Download it here and add it to your Processing classpath (import it). After successfully doing so, you can use JEP like this:

void setup() {
  org.nfunk.jep.JEP parser = new org.nfunk.jep.JEP();
  parser.addComplex();
  try {
    parser.parseExpression("(1+2*i) + (3+8*i)");
    println(parser.getComplexValue());
  } catch(Exception e) {
    e.printStackTrace();
  }
}

which produces the (expected) output: (4.0, 10.0)