public float getAmplitudeRatio() {
        return mAmplitudeRatio;
    }
Set water level according to <code>waterLevelRatio</code>.

@param waterLevelRatio Should be 0 ~ 1. Default to be 0.5.
                       Ratio of water level to WaveView height.
library/src/main/java/com/gelitenight/waveview/library/WaveView.java