Positioning an arrow between two values (Metapost)

Positioning an arrow between two values (Metapost)

[Fabrice Couvreur]

[-- Attachment #1.1: Type: text/plain, Size: 593 bytes --]

Hi,
I went from PSTricks to Metapost (Metafun) gradually. For positioning arrows
between two values in an array of variations, I used a command like this \
ncline {A}{B}, which avoids fumbling.
Can we do the same with Metapost ?
The idea would be to convert the value into a path or an image, much like in
the code below.

\starttext
\startMPcode
u:=1cm ;
path p, q ;
p=fullsquare scaled u ;
q=fullsquare scaled u shifted (4u,-2u) ;
draw p ;
draw q ;
drawarrow center p--center q ;
label(btex $5$ etex,center p) ;
label(btex $-2 $ etex,center q) ;
\stopMPcode
\stoptext

Best regards,
Fabrice

[-- Attachment #1.2: Type: text/html, Size: 1890 bytes --]

[-- Attachment #2: Type: text/plain, Size: 485 bytes --]

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

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________

Re: Positioning an arrow between two values (Metapost)

[Troy Henderson]

[-- Attachment #1.1: Type: text/plain, Size: 857 bytes --]

>
> \starttext
> \startMPcode
> u:=1cm ;
> path p, q ;
> p=fullsquare scaled u ;
> q=fullsquare scaled u shifted (4u,-2u) ;
> draw p ;
> draw q ;
> drawarrow center p--center q ;
> label(btex $5$ etex,center p) ;
> label(btex $-2 $ etex,center q) ;
> \stopMPcode
> \stoptext
>

How about something like below.  I'm not sure exactly how ncline works in
PStricks, but this macro takes 4 arguments, namely a point, its
corresponding label, a second point, and its corresponding label.

\starttext
\startMPcode

vardef ncline (expr A,h,B,k) =
    save p,q;
    path p,q;
    label(h,A);
    p:=fullsquare scaled u shifted A;
    draw p;
    label(k,B);
    q:=fullsquare scaled u shifted B;
    draw q;
    drawarrow (A--B) cutbefore p cutafter q;
enddef;

u:=1cm ;
ncline(origin,btex $5$ etex,(4*u,-2*u),btex $-2$ etex);

\stopMPcode
\stoptext

Troy Henderson

[-- Attachment #1.2: Type: text/html, Size: 1374 bytes --]

[-- Attachment #2: Type: text/plain, Size: 485 bytes --]

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

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________

Re: Positioning an arrow between two values (Metapost)

[Fabrice]

Hi Troy,
Thank you, this macro is very nice ; it matches what I want to do even 
if I would like a smaller space between the arrow and labels.
Best regards,
Fabrice
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://tex.aanhet.net
archive  : http://foundry.supelec.fr/projects/contextrev/
wiki     : http://contextgarden.net
___________________________________________________________________________________