Am 01.09.22 um 15:40 schrieb Taco Hoekwater:

Adding grouping makes sense:

...

def Moire(expr size)(text densities)=

begingroup endgroup

As that at least makes it an expression instead of a statement list.

But also depthless() is never defined?

Oops, I forgot to copy that part (confusing source...) It still doesn’t compile: --- \setupbodyfont[plex,ss,8bp] \startreusableMPgraphic{moiree} % 1994 by Bogusław Jackowski (GUST) defaultfont := "\truefontname{Sans}"; pickup pencircle scaled 0.3bp; defaultscale := .8; linecap := butt; labeloffset := 1.5bp; defaultthickness:=.3bp; % 5 pixels at 1200 dpi % tertiarydef p ulshiftedto s = p shifted (s-ulcorner(p)) enddef; vardef depthless(expr p) = save p_; picture p_; p_:=p if string p: infont defaultfont scaled defaultscale fi; setbounds p_ to (xpart(llcorner p_),0)--(xpart(lrcorner p_),0)-- urcorner(p_)--ulcorner(p_)--cycle; p_ enddef; def Moire(expr size)(text densities)= begingroup save dn,a,b,k,labit,n,p,q,s,xs; n := 32; dn := 0; for i := densities: d[incr dn] := abs(i); if i>1: labit[dn]:=1; fi endfor a := min(d[1],d[dn]); b := max(d[1],d[dn]); image( for i=-n upto n: draw (0,i*in/a)--(size,i*in/b); %withpen pencircle scaled 3/5defaultthickness; endfor for i=1 upto dn: k:=(a/d[i]-1)/(a/b-1); if known labit[i]: string s; s:=decimal(d[i]); xs:=0; picture p,q; q := p := depthless(s); if i=dn: q := depthless(s & " lpi"); xs := width(q)-width(p); fi label.top(q, (k*size+1/2xs, n*in/a+1.5mm)); fi draw (k*size, n*in/a+1.5mm)--(k*size, k[n*in/a,n*in/b]+.5mm); draw (k*size, -n*in/a-1.5mm)--(k*size, -k[n*in/a,n*in/b]-.5mm); endfor ) endgroup; enddef; draw Moire(57.5mm)(200, 175, 150, 125, 100, 75); % ulshiftedto (142mm, 38.5mm); \stopreusableMPgraphic \starttext \reuseMPgraphic{moiree} \stoptext

Am 01.09.22 um 18:45 schrieb Taco Hoekwater:

...

On 1 Sep 2022, at 18:28, Henning Hraban Ramm via ntg-context wrote:

Am 01.09.22 um 15:40 schrieb Taco Hoekwater:

...

Adding grouping makes sense:

...

def Moire(expr size)(text densities)=

begingroup endgroup As that at least makes it an expression instead of a statement list. But also depthless() is never defined?

Oops, I forgot to copy that part (confusing source...)

It still doesn’t compile:

Missing definition of “width()”, from this line:

...

xs := width(q)-width(p);

Adding that should do the trick.

YES, thank you! I never know which function is part of MetaPost/MetaFun, my editor’s syntax highlighting is incomplete... Hraban