Re: Buffered metapost function freezes random numbers

[Hans Hagen <pragma@wxs.nl>]

On 5/25/2016 7:09 PM, DesdeChaves wrote:
> For educational purposes I try to simulate a ammeter for reading practice.
> I would like create six or more ammeter with different readings, but i'm
> not able to do that because metapost create the same random number every
> time I call the buffer that defines my ammeter.
>
> How can I fix that?
>
> Thanks
>
> Jorge
>
> My code:
>
>
> \startbuffer[ammeter]
> \startMPcode
>    r := 4cm; len := 10bp; min_thickness := 1.75bp; hour_thickness := 3bp;
>       path cadran; cadran = fullcircle scaled (2r);
>      numeric escala;
>      escala := 0;
>  for i = 50 upto 70:
>         if i mod 5 = 0:
>           j := i div 5; angl := 90-30j;
>           freelabel("\tfb\bf" & decimal escala, (r+len)*dir angl, r*dir
> angl);
>           draw ((r, 0) -- (r - len, 0)) rotated angl withpen pencircle
> scaled min_thickness;
>           escala:= escala + 0.5;
>         else:
>           angl := 90 - 6i;
>           draw ((r, 0) -- (r - .5len, 0)) rotated angl;
>         fi
>  endfor
> pickup pencircle scaled min_thickness;
> numeric  minute;
> %randomseed := uniformdeviate infinity;
> minute:= 50 + uniformdeviate(20);
>  pair A, B, C;
> A:=1.6r*right+.5r*up;
> C:=1.6r*right+.8r*up;
> B:=1.1r*left;
>  drawarrow origin -- r*dir(90-minute*6) cutends (0, 1.5len);
> fill fullcircle scaled .75len;
> draw unitsquare xscaled 3.2r yscaled 1.5r shifted B;
> label("\tfb I (A)", 1.2r*up+1.6r*right) withcolor red;
> draw fullcircle scaled 2len shifted A;
> draw fullcircle scaled 2len shifted C;
> \stopMPcode
> \stopbuffer
>
>
>
> \startbuffer[programa]
>
> \placefigure[center,nonumber]{}{
> \startcombination[2*1]
> {\externalfigure[ammeter][type=buffer,width=8cm]}{\_\_\_\_\_\_\_\_\_\_$\pm$\_\_\_\_\_\_\_\_}
> {\externalfigure[ammeter][type=buffer,width=8cm]}{\_\_\_\_\_\_\_\_\_\_$\pm$\_\_\_\_\_\_\_\_}
> }
> \stopcombination

\stopcombination in wrong spot

> \stopbuffer
>
>
> \starttext
>
> \dorecurse{3} {\getbuffer[programa]}
>
> \stoptext

disable object reuse

\startplacefigure
     \startcombination[2*1]
 
{\externalfigure[ammeter][type=buffer,object=no,width=8cm]}{\_\_\_\_\_\_\_\_\_\_$\pm$\_\_\_\_\_\_\_\_}
 
{\externalfigure[ammeter][type=buffer,object=no,width=8cm]}{\_\_\_\_\_\_\_\_\_\_$\pm$\_\_\_\_\_\_\_\_}
     \stopcombination
\stopplacefigure

\stopbuffer



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                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
       tel: 038 477 53 69 | www.pragma-ade.com | www.pragma-pod.nl
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