Plotting 3D function and points in SPSS - spss

Question

I want to plot a 3D graph with points (I think I have managed that) and also fitting a mathematical function of set of that points. My variable V1 can assume two values 2 or 4. So, If V1 is equal to 2 a function is plotting, else if V1 is equal to 4 other function is plotting. When I try do it this message appear:
Erro de GPL: algebra(iter(5000,1000000,10)DOIF(V1=2).)
Expecting ( or + or * or /: iter(5000,1000000,10)DOIF(V1=2)
My code:
> GGRAPH /GRAPHDATASET NAME="graphdataset" VARIABLES=V2 pacpop V1
> MISSING=LISTWISE REPORTMISSING=NO /GRAPHSPEC SOURCE=INLINE. BEGIN
> GPL SOURCE: s=userSource(id("graphdataset"))
>DATA:V2=col(source(s), name("V2"))
>DATA: pacpop=col(source(s),name("pacpop"))
>DATA: V1=col(source(s), name("V1"),unit.category())
>COORD: rect(dim(1,2,3))
>GUIDE: axis(dim(1),label("Sexo"))
> GUIDE: axis(dim(2), label("Rendimento Mensal"))
> GUIDE: axis(dim(3), label("pacpop"))
>SCALE: log(dim(2), base(10))
>SCALE: log(dim(3), base(10))
>SCALE: cat(dim(1), include("2", "4"))
> ELEMENT: point(position(V1*V2*pacpop))
>DATA: p = iter(0,5000,1)
> DATA: q = iter(5000,1000000,10)
>DATA: x = iter(0,5000,1)
>DATA: z =iter(5000,1000000,10)
>DO IF (V1=2).
>TRANS: y =eval(100*exp((-x/1654.97))
> TRANS: w = eval((10**8.865)/(z**2.186))
> ELEMENT: line(position(V1*x*y),color.interior(color."ff0000"))
> ELEMENT: line(position(V1*z*w), color.interior(color."ff0000"))
> ELSE.
> TRANS: r = eval(100*exp((-p/1415.97))
>TRANS: s = eval((10**7.065)/(q**2.216))
>ELEMENT:line(position(V1*p*r),color.interior(color."ff0000"))
ELEMENT:line(position(V1*q*s), color.interior(color."ff0000"))
>END IF.
> END GPL.

Answer 1

There is no need to use 3d here. Since V1 can only take two values, you can simply superimpose those lines onto the same plot and see where they diverge, example below. Note I changed p to range from 1 to 5000, you can't take the log of 0.
GGRAPH /GRAPHSPEC SOURCE=INLINE.
BEGIN GPL
COORD: rect(dim(1,2))
DATA: p = iter(1,5000,1)
DATA: q = iter(5000,1000000,10)
TRANS: y =eval(100*exp((-p/1654.97))
TRANS: w = eval((10**8.865)/(q**2.186))
TRANS: r = eval(100*exp((-p/1415.97))
TRANS: s = eval((10**7.065)/(q**2.216))
TRANS: V2 = eval("V1=2")
TRANS: V4 = eval("V1=4")
SCALE: log(dim(1), base(10))
SCALE: log(dim(2), base(10))
GUIDE: axis(dim(3), opposite())
ELEMENT: line(position(p*y), color.interior(color.red))
ELEMENT: line(position(q*w), color.interior(color.pink))
ELEMENT: line(position(p*r),color.interior(color.blue))
ELEMENT: line(position(q*s), color.interior(color.lightblue))
END GPL.
You can work out from there to plot 3d if you really want to, but I would not recommend it.