Here you can find the source of tan(final float value)
public static final float tan(final float value)
//package com.java2s; //License from project: Open Source License public class Main { private static float[] TG_TABLE = new float[361]; public static final float tan(final float value) { final int temp; if (value > 0) { if ((int) value > 360f) { if ((temp = ((int) value - ((int) (value / 360f)) * 360)) != 0) { return TG_TABLE[temp]; } else { return TG_TABLE[360]; }//from w w w .j a v a 2 s.com } else { return TG_TABLE[(int) (value)]; } } else if ((-(int) value) > 360f) { if ((temp = (-((int) value - ((int) (value / 360f)) * 360))) != 0) { return TG_TABLE[temp]; } else { return TG_TABLE[360]; } } else { return TG_TABLE[-(int) (value)]; } //return TG_TABLE[(int)(value)]; } public static final double tan(final double value) { final int temp; if (value > 0) { if ((int) value > 360d) { if ((temp = ((int) value - ((int) (value / 360d)) * 360)) != 0) { return (double) TG_TABLE[temp]; } else { return (double) TG_TABLE[360]; } } else { return (double) TG_TABLE[(int) (value)]; } } else if ((-(int) value) > 360d) { if ((temp = (-((int) value - ((int) (value / 360d)) * 360))) != 0) { return (double) TG_TABLE[temp]; } else { return (double) TG_TABLE[360]; } } else { return (double) TG_TABLE[-(int) (value)]; } //return (double)TG_TABLE[(int)(value)]; } }