Iterando sui numeri interi con questo codice:
`
% !TEX TS-program = LuaLaTeX
\documentclass{standalone}
\usepackage{pgfplots}
\usepackage{luacode}
\begin{luacode*}
function Liss(val,t)
return math.sin(val*t)
end
function stampa_pgf(a,b,s)
tex.sprint(“\\addplot[mark=, red, smooth] coordinates{“)
— 2pi_greco/500=0.0125663 — valore con 500 campioni
— ansys suggerisce di usare per il calcolo di step la formula
— step=string.format(“\%.50f”,2*math.pi/s)
— step=2*math.pi/s
step=string.format(“\%.50f”,2*math.pi/s)
— for i=0,2*math.pi,step do
for i=0,s,1 do
u= i*step
x=Liss(a,u)
y=Liss(b,u)
tex.sprint(“(“..x..”,”..y..”)”)
end
tex.sprint(“};”)
end
\end{luacode*}
\newcommand\myaddplot[3]{\directlua{stampa_pgf(#1,#2,#3)}}
\begin{document}
\begin{tikzpicture}
\begin{axis}
\myaddplot{7}{2}{100}
\end{axis}
\end{tikzpicture}
\end{document}
%%% Local Variables:
%%% mode: latex
%%% TeX-engine: luatex
%%% TeX-master: t
%%% End:
`
che itera sui numeri interi la curva si chiude sempre. Con 30 campioni viene uno schifo; con 100 campioni è leggermente deformata, ma difficile da notarlo ad occhio nudo; con 200 campioni viene benissimo.
Occupazione di memoria: dal file log con 100 campioni si legge
`
Here is how much of LuaTeX's memory you used:
17683 strings out of 494981
100000,552014 words of node,token memory allocated
3419 words of node memory still in use:
77 hlist, 1 vlist, 1 rule, 20 math, 310 glue, 22 glyph, 56 glue_spec, 1 writ
e, 311 pdf_literal, 10 pdf_colorstack nodes
avail lists: 1:1,2:34,3:313,4:362,5:1,6:30,7:1,9:83
20513 multiletter control sequences out of 65536+200000
25 fonts using 994935 bytes
63i,10n,82p,653b,1495s stack positions out of 5000i,500n,10000p,200000b,50000s
`
Con 200 campioni si legge invece:
`
Here is how much of LuaTeX's memory you used:
17715 strings out of 494981
100000,662416 words of node,token memory allocated
4119 words of node memory still in use:
77 hlist, 1 vlist, 1 rule, 20 math, 410 glue, 22 glyph, 56 glue_spec, 1 writ
e, 411 pdf_literal, 10 pdf_colorstack nodes
avail lists: 1:1,2:34,3:413,4:462,5:1,6:30,7:1,9:83
20545 multiletter control sequences out of 65536+200000
25 fonts using 994935 bytes
63i,10n,82p,653b,1495s stack positions out of 5000i,500n,10000p,200000b,50000s
`
A quanto pare sono aumentati di 100 unità soltanto i glue nodes. Ma non sono in grado di dire quanti ce ne fossero disponibili.