Example usage for java.lang Math PI

Introduction

In this page you can find the example usage for java.lang Math PI.

Prototype

double PI

To view the source code for java.lang Math PI.

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Document

The double value that is closer than any other to pi, the ratio of the circumference of a circle to its diameter.

Usage

From source file:Main.java

private static float getY(double angle, double radius) {
    return (float) (Math.sin(angle + Math.PI / 2) * radius);
}

From source file:Main.java

public static float[] createSoundDataInFloatArray(int bufferSamples, final int sampleRate,
        final double frequency, double sweep) {
    final double rad = 2 * Math.PI * frequency / sampleRate;
    float[] vaf = new float[bufferSamples];
    sweep = Math.PI * sweep / ((double) sampleRate * vaf.length);
    for (int j = 0; j < vaf.length; j++) {
        vaf[j] = (float) (Math.sin(j * (rad + j * sweep)));
    }//from  w  w  w.j  ava  2 s  . c om
    return vaf;
}

From source file:Main.java

public static short[] createSoundDataInShortArray(int bufferSamples, final int sampleRate,
        final double frequency, double sweep) {
    final double rad = 2 * Math.PI * frequency / sampleRate;
    short[] vai = new short[bufferSamples];
    sweep = Math.PI * sweep / ((double) sampleRate * vai.length);
    for (int j = 0; j < vai.length; j++) {
        vai[j] = (short) (Math.sin(j * (rad + j * sweep)) * Short.MAX_VALUE);
    }//w w  w. j a v  a2  s. c  om
    return vai;
}

From source file:Main.java

public static byte[] createSoundDataInByteArray(int bufferSamples, final int sampleRate, final double frequency,
        double sweep) {
    final double rad = 2 * Math.PI * frequency / sampleRate;
    byte[] vai = new byte[bufferSamples];
    sweep = Math.PI * sweep / ((double) sampleRate * vai.length);
    for (int j = 0; j < vai.length; j++) {
        int unsigned = (int) (Math.sin(j * (rad + j * sweep)) * Byte.MAX_VALUE) + Byte.MAX_VALUE & 0xFF;
        vai[j] = (byte) unsigned;
    }/*from w ww .j  a v  a  2s.  c o m*/
    return vai;
}

From source file:Main.java

/**
 * radian to angle/*  www . ja  v a  2 s . co m*/
 *
 * @param radian radian
 * @return angle
 */
public static double radian2Angle(double radian) {
    return radian / Math.PI * 180;
}

From source file:Main.java

/**
 * angle to radian/*from  www . jav  a2s  . co m*/
 *
 * @param angle angle
 * @return radian
 */
public static double angle2Radian(double angle) {
    return angle / 180 * Math.PI;
}

From source file:Main.java

/**
 * Metoda care calculeaza viteza cu care se deplaseaza intre 2 coordonate
 * date(Lat+long) intr-un interval de timp [time_1,time_2]. Calculam
 * distanta dintre cele doua coordonate folosind formula " Great-circle
 * distance" viteza = distanta transformata in m/diferenta dintre cei 2
 * timpi primiti ca parametru/*w  w  w.  j  a  v a2  s  .  c o  m*/
 */
public static double computeSpeed(double lat_1, double long_1, long time_1, double lat_2, double long_2,
        long time_2) {
    double speed; // speed->m/s
    double distanceKm;
    double distanceM;
    long time;
    double r = 6378.137;

    double e = (double) Math.acos(
            Math.sin(lat_1) * Math.sin(lat_2) + Math.cos(lat_1) * Math.cos(lat_2) * Math.cos(long_2 - long_1));
    e = e / 180 * (double) Math.PI;
    distanceKm = e * r;
    distanceM = distanceKm * 1000;
    time = (time_2 - time_1) / 1000;
    speed = distanceM / time;

    return speed;
}

From source file:Main.java

private static double reduceSinAngle(double radians) {
    radians %= Math.PI * 2.0;
    if (Math.abs(radians) > Math.PI) {
        radians = radians - (Math.PI * 2.0);
    }// ww w  .j a  v a 2  s.co  m
    if (Math.abs(radians) > Math.PI / 2) {
        radians = Math.PI - radians;
    }
    return radians;
}

From source file:Main.java

/**
 * @param deg/*from ww w  . j  a va 2  s .c om*/
 * @return
 */
public static float calculatePiValueFromDegrees(float deg) {
    return roundDecimals(((-(Math.PI / 180) * deg + Math.PI / 2) / Math.PI), 3);
}

From source file:Main.java

private static double calcPhase(int step, float freq, int samplingRate) {
    return Math.PI * step * freq / samplingRate;
}