了解此代码中的Pinescript NZ函数用法

Question

请帮助我确认我对实现Kalman过滤器的以下Pinescript功能的理解。我在代码中包括了一些评论，我对代码要完成的内容进行了理解/问题。谢谢！

kalman(x, g) =>
    //x is a moving average (MA) and g is a constant
    kf = 0.0 
    dk = x - nz(kf[1], x) //Calculate the difference between current bar's MA value and 
                          //MA value at the previous bar?
    smooth = nz(kf[1], x) + dk * math.sqrt(g * 2) //Is nz(kf[1], x) equal to the previous 
                                                  //bar's MA value?
    velo = 0.0
    velo := nz(velo[1], 0) + g * dk //Not sure what nz(velo[1], 0) is supposed to model. 
                                    //Is that building velo by adding velo's value on the 
                                    //previous bar to g*dk?
    kf := smooth + velo

Answer 1

nz（）将用给定值替换Na值。

nz（kf [1]，x）将检查kf [1]（kf在上一个bar上的值）为na。如果是NA，它将用X替换它。