L := hfarray(1 .. 3,1 .. 3);
the line above means x and y have 3 values.

how about the third cordinate it shoud be 9??

makearray:= proc()
> local L, i, x, y, xp;
> L := hfarray(1 .. 3,1 .. 2);
> x:= 0.6; y := 0.2;
> for i to 3 do
>   xp := 1+y-1.4*x^2;
>   y  := .3*x;
>   x  := xp;
> od;
> for i to 3 do
>   xp := 1+y-1.4*x^2;
>   y  := .3*x;
>   x  := xp;
>   L[i,1]:= x; L[i,2]:= y;
> od;
> L
> end:L:= evalhf(makearray());
how can I do it in plot3d

Thanks for your respond.

If x and y and f(x,y) are inside the  for loop it works to put the three lines in the loops  I'm not sure

x:=RandomTools:-Generate(list(float,10)):
y:=RandomTools:-Generate(list(float,10)):

f:=RandomTools:-Generate(list(float,1000)):
f:=(x,y)->sin(x+y);
 

I want to creat a sequence in order to plot3d,

points:=[seq([x[i],y[i],f(x,y)[i]],i=1..100)];