Simple linear regression algorithm

/** *  Simple linear regression algorithm  *  @param  array y axis data  *  @param  array x axis data   *  @returns  array (SLOPE,INTERCEPT,R2)  */function linearregression (y, x)  {     var lr = {};    var n = y.length;     var sum_x = 0;    var sum_y = 0;     var sum_xy = 0;    var sum_xx = 0;     var sum_yy = 0;    for  (var i = 0;  i < y.length; i++)  {        sum_x +=  x[i];        sum_y += y[i];         sum_xy +=  (X[i] * y[i]);         sum_xx +=  (X[i] * x[i]);        sum_yy +=  (y[i] * y [i]);     }    lr[' slope '] =  (n * sum_xy - sum _x * sum_y)  /  (n * sum_xx - sum_x * sum_x);     lr[' intercept '] =  (sum_y - lr.slope * sum_x)  / n;     lr[' R2 '] = math.pow (n * sum_xy - sum_x * sum_y)  / math.sqrt (n * sum_xx - sum_x * sum_x)  *  (n *  sum_yy - sum_y * sum_y),  2);    return lr;};

Algorithm Detailed: http://wiki.mbalib.com/wiki/%E4%B8%80%E5%85%83%E7%BA%BF%E6%80%A7%E5%9B%9E%E5%BD%92%E9%A2%84%E6%B5%8B%E6%B3%95

B=slope,a=intercept

Y=a+bx

Simple linear regression algorithm