Re: Metapost label - Truncating digits after decimal point

[Taco Hoekwater <taco@elvenkind.com>]

Curiouslearn wrote:
> Hi,
> 
> Is it possible to truncate the digits after decimal point in Metapost
> when using textext()? Please see the minimal example below which
> produces 1.84375. Can I just keep the first digit and have it produce
> 1.8 ?

Here is a helper macro for you:

def trunc_digits(expr n, origs) =
   hide(
     string s, tmp;
     numeric ii, e;
     e := -1;
     for i=1 upto length(origs):
       ii := i;
       tmp := substring (i-1,i) of origs;
       if tmp = ".": if n=0: ii:=ii-1; exitif true; fi e:=0; fi
       if e>=0: e := e+1; exitif e>n;  fi
     endfor;
     s:=substring(0,ii) of origs; )
   s
enddef;


When run this macro with the result of decimal() as second argument,
it will create a new string as many fractional digits as you specify
in the first argument:

   label.lft(textext(trunc_digits(1,decimal f(5))),(0,f(5)) scaled u);	

Best wishes,
Taco
___________________________________________________________________________________
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
___________________________________________________________________________________