AttenuationInterpolator.java

public class AttenuationInterpolator implements Interpolator {

    public AttenuationInterpolator() {
    }

    @SuppressWarnings({"UnusedDeclaration"})
    public AttenuationInterpolator(Context context, AttributeSet attrs) {
    }

    @Override
    public float getInterpolation(float v) {
        //y = -e^-x * cos14.12x + 1

        return -1 * (float) Math.pow(Math.E, -3 * v) * (float) Math.cos(20.42034 * v) + 1;
    }
}