Here you can find the source of interpolate(double a, double b, double d)
public static double interpolate(double a, double b, double d)
//package com.java2s; //License from project: LGPL public class Main { public static double interpolate(double a, double b, double d) { return a + (b - a) * d; }//from ww w .ja va 2 s . c o m public static float interpolate(float a, float b, float d) { return a + (b - a) * d; } }