Modify PlayThatTune to take additional command-line arguments that control the v

Question

Modify PlayThatTune to take additional command-line arguments that control the volume (multiply each sample value by the volume) and the tempo (multiply each note's duration by the tempo).

public class PlayThatTune {

public static void main(String[] args) {

// repeat as long as there are more integers to read in
while (!StdIn.isEmpty()) {

// read in the pitch, where 0 = Concert A (A4)
int pitch = StdIn.readInt();

// read in duration in seconds
double duration = StdIn.readDouble();

// build sine wave with desired frequency
double hz = 440 * Math.pow(2, pitch / 12.0);
int n = (int) (StdAudio.SAMPLE_RATE * duration);
double[] a = new double[n+1];
for (int i = 0; i <= n; i++) {
a[i] = Math.sin(2 * Math.PI * i * hz / StdAudio.SAMPLE_RATE);
}

// play it using standard audio
StdAudio.play(a);
}
}
}

Explanation / Answer

public class PlayThatTune {

public static void main(String[] args) {

// repeat as long as there are more integers to read in
while (!StdIn.isEmpty()) {

// read in the pitch, where 0 = Concert A (A4)
int pitch = StdIn.readInt();

// read in duration in seconds
double duration = StdIn.readDouble();

// build sine wave with desired frequency
double hz = 440 * Math.pow(2, pitch / 12.0);
int n = (int) (StdAudio.SAMPLE_RATE * duration);
double[] a = new double[n+1];
for (int i = 0; i <= n; i++) {
a[i] = Math.sin(2 * Math.PI * i * hz / StdAudio.SAMPLE_RATE);
}

// play it using standard audio
StdAudio.play(a);
}
}
}

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