MACD calculator. Not a standalone Java program but some Java code as good as pseudocode.

MACDCalculator.java

import java.util.ArrayList;

public class MACDCalculator extends SimpleCalculator {

  private float ema1alpha;
  private float ema2alpha;
  private float signalalpha;
  private float[] pema1;
  private float[] pema2;
  private float[] psignal;

  MACDCalculator(ArrayList<Float> args) {
    this.ema1alpha = args.get(0);
    this.ema2alpha = args.get(1);
    this.signalalpha = args.get(2);
    this.pema1 = null;
    this.pema2 = null;
    this.psignal = null;
  }

  @Override
  public float[] calculate(float[] values) {
    float[] res;
    if (this.pema1 == null){
      this.pema1 = values.clone();
      this.pema2 = values.clone();
      this.psignal = values.clone();
      res = values.clone();
    }
    else{
      res = new float[values.length];
      for (int i = 0; i < values.length; i++){
        this.pema1[i] = this.ema1alpha * values[i] + (1-this.ema1alpha) * this.pema1[i];
        this.pema2[i] = this.ema2alpha * values[i] + (1-this.ema2alpha) * this.pema2[i];
        this.psignal[i] = this.signalalpha * (this.pema1[i]-this.pema2[i]) + (1-this.signalalpha) * this.psignal[i];
        res[i] = this.pema1[i] - this.pema2[i] - this.psignal[i];
      }
    }
    return res;
  }
}