Pine script 将v2转换为v4此脚本上的指示器

我无法将此指示器v2转换为v4。请帮助我了解这个指标：

第11行：未声明的标识符“ssmooth”

这将起作用：

//@version=4
study("xxx",shorttitle="x")

var float ssmooth  = na
var float ssmooth2 = na
var float ssmooth3 = na

p = close
len = input(8,minval=1,title="Length")
f = (1.414*3.14159)/len
a = exp(-f)
c2 = 2*a*cos(f)
c3 = -a*a
c1 = 1-c2-c3
ssmooth := c1*(p+p[1])*0.5+c2*nz(ssmooth[1])+c3*nz(ssmooth[2])

len2 = input(13,minval=1,title="Length")
f2 = (1.414*3.14159)/len2
a2 = exp(-f2)
c22 = 2*a2*cos(f2)
c32 = -a2*a2
c12 = 1-c22-c32
ssmooth2 := c12*(p+p[1])*0.5+c22*nz(ssmooth2[1])+c32*nz(ssmooth2[2])

macd = (ssmooth - ssmooth2)*10000000
len3 = input(3,minval=1,title="Length")
f3 = (1.414*3.14159)/len3
a3 = exp(-f3)
c23 = 2*a3*cos(f3)
c33 = -a3*a3
c13 = 1-c23-c33
ssmooth3 := c13*(macd+macd[1])*0.5+c23*nz(ssmooth3[1])+c33*nz(ssmooth3[2])

plot(macd, color=color.red, linewidth=2)
plot(ssmooth3, color=color.blue, linewidth=2)

//@version=4
study("xxx",shorttitle="x")

var float ssmooth  = na
var float ssmooth2 = na
var float ssmooth3 = na

p = close
len = input(8,minval=1,title="Length")
f = (1.414*3.14159)/len
a = exp(-f)
c2 = 2*a*cos(f)
c3 = -a*a
c1 = 1-c2-c3
ssmooth := c1*(p+p[1])*0.5+c2*nz(ssmooth[1])+c3*nz(ssmooth[2])

len2 = input(13,minval=1,title="Length")
f2 = (1.414*3.14159)/len2
a2 = exp(-f2)
c22 = 2*a2*cos(f2)
c32 = -a2*a2
c12 = 1-c22-c32
ssmooth2 := c12*(p+p[1])*0.5+c22*nz(ssmooth2[1])+c32*nz(ssmooth2[2])

macd = (ssmooth - ssmooth2)*10000000
len3 = input(3,minval=1,title="Length")
f3 = (1.414*3.14159)/len3
a3 = exp(-f3)
c23 = 2*a3*cos(f3)
c33 = -a3*a3
c13 = 1-c23-c33
ssmooth3 := c13*(macd+macd[1])*0.5+c23*nz(ssmooth3[1])+c33*nz(ssmooth3[2])

plot(macd, color=color.red, linewidth=2)
plot(ssmooth3, color=color.blue, linewidth=2)