Hi Taco,
I knew I wouldn't be able to explain what was happening.
The code works perfectly and the figure is clearly visible in the component chapter-14 :

\startcomponent[chapter-14]
\startMPpage
...
\stopMPpage
\stopcomponent

But if I compile my project, it disappears !!

\startproduct[terminale-manual]
 \startbodymatter
      \component[chapter-1]
      \component[chapter-2]
      \component[chapter-3]
      \component[chapter-4]
      \component[chapter-5]
      \component[chapter-6]
      \component[chapter-7]
      \component[chapter-8]
      \component[chapter-9]
      \component[chapter-10]
      \component[chapter-11]
      \component[chapter-12]
      \component[chapter-13]
      \component[chapter-14]
    \stopbodymatter
\stopproduct

Le jeu. 25 avr. 2024 à 13:36, Taco Hoekwater <taco@bittext.nl> a écrit :
H Fabrice,

You did not provide a good minimum test because the graph by itself renders fine:



Best wishes,
Taco
(if all else fails, you can replace \startMPcode with \startMPpage and generate a standalone graph that way)

> On 25 Apr 2024, at 12:27, Fabrice Couvreur <fabrice1.couvreur@gmail.com> wrote:
>
> Hi,
> I don't know if I can explain the problem I'm having. I made a project with 14 chapters. In each of them, there are graphics embedding metapost code. I proceed as follows : I compile each chapter alone with lmtx then I compile the project containing the 14 chapters. I didn't encounter any problems except with a graphic from the last chapter. It is indeed in chapter 14 but not in the project ! I give the code for this graph.
> Thanks.
> Fabrice
>
> \startMPcode
>
>                interim linejoin := mitered;
>                interim ahangle := 30;
>                numeric u, pi;
>         
>                pi = 3.141592653589793;
>                u = 1.5cm;
>         
>                vardef graph_of_function (suffix f) (expr xmin, xmax, xsep) =
>                   for x = xmin step xsep until xmax: (x, f(x)) .. endfor (xmax, f(xmax))
>                enddef ;
>
>                vardef vline (suffix f, g) (expr x) = (x, min(f(x), g(x))) -- (x, max(f(x),g(x))) enddef;
>
>                vardef area_between_functions (suffix f, g)(expr a, b, xsep) =
>                   buildcycle(graph_of_function(f, a, b, xsep), vline(f, g, b),
>                   reverse graph_of_function(g, a, b, xsep), reverse vline(f, g, a))
>                enddef;
>
>                vardef xaxis (expr xmin, xmax) = (xmin, 0) -- (xmax, 0) enddef ;
>                vardef yaxis (expr ymin, ymax) = (0, ymin) -- (0, ymax) enddef ;
>

>                xmin:=-pi/2; xmax := 3*pi/2;
>                ymin := -1.5; ymax := 5;
>           
>
>                vardef f(expr x)= exp(-x)*(-cos(x)+sin(x)+1) enddef;
>                vardef g(expr x)=-exp(-x)*cos(x) enddef;
>                path C_f, C_g;
>                C_f = graph_of_function(f,xmin, xmax, .1);
>                C_g = graph_of_function(g, xmin, xmax, .1);
>
>                a := xpart(C_f intersectionpoint C_g);
>                b := xpart(reverse C_f intersectionpoint reverse C_g);
>
>                fill (area_between_functions(f, g, a, b, 0.1)) scaled u withcolor 0.4[white, blue];
>                draw C_f scaled u withcolor blue;
>                draw C_g scaled u withcolor blue;
>               
>           
>            \stopMPcode
> ___________________________________________________________________________________
> If your question is of interest to others as well, please add an entry to the Wiki!
>
> maillist : ntg-context@ntg.nl / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
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> ___________________________________________________________________________________


Taco Hoekwater              E: taco@bittext.nl
genderfluid (all pronouns)


___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / https://mailman.ntg.nl/mailman3/lists/ntg-context.ntg.nl
webpage  : https://www.pragma-ade.nl / https://context.aanhet.net (mirror)
archive  : https://github.com/contextgarden/context
wiki     : https://wiki.contextgarden.net
___________________________________________________________________________________