How to write a recursion function correctly?

kennyLiao

Hi everyone,

I tried to write a recursion function to calc a number. There seems to have no syntax or runtime error, but I just could not get the result right (result I got are all zeros). I need your help to inspect my codes here. Thanks a lot!

    FloatList RSVs = new FloatList();
    void setup() {

      for (int i = 20; i < 100; i++) {
        float ram = random(-20, 120);
        RSVs.append(ram);
      }
      println(calcK(3));

      getKs();

      printArray(Ks);
    }


    FloatList Ks = new FloatList();

    void getKs() {

      for (int i = 0; i < RSVs.size(); i++) {

        Ks.append(calcK(i));
      }
    }


    float calcK(int RSVIndex) {
      float K;

      if (RSVIndex >= 0) {
        K = (6-1)/6*calcK(RSVIndex-1)+1/6*RSVs.get(RSVIndex);
      } else {
        K = 50;
      }
      return K;
    }

GoToLoop

K = (6-1)/6*calcK(RSVIndex-1)+1/6*RSVs.get(RSVIndex);

(6-1)/6 = 0 & 0 * calcK(RSVIndex-1) = 0
1/6 = 0 & 0 * RSVs.get(RSVIndex) = 0

0 + 0 = 0 thus K = 0!

https://forum.Processing.org/two/discussions/tagged/division
https://forum.Processing.org/two/discussions/tagged/float

kennyLiao

@GoToLoop, Thanks a lot! How careless I am to miss it