🚀 go-pugleaf

In article <15SEP199203465090@reg.triumf.ca> asnd@reg.triumf.ca (Donald Arseneau) writes:
>In article <1992Sep14.220128.16318@Princeton.EDU>, tvz@zandtwerk.Princeton.EDU () writes...
>>Here is a macro for fixed point addition.
>> 
>>USAGE \FPadd{num1}{num2}\cs
>> 
>>This sets \cs to num1+num2.
>
>
>If the somewhat-limited precision of TeX's lengths is enough, how about
>
>\def\FPadd#1#2#3{\FPdim#1\p@ \advance\FPdim#2\p@
>  \edef#3{\expandafter\pointless\the\FPdim}}
>
>\newdimen\FPdim
>
>\begingroup 
>\catcode`P=12 \catcode`T=12 
>\lowercase{
>\endgroup\def\pointless #1PT{#1}
>}
>
>The final incantation is to get pt with catcode 12 into the syntax 
>of \pointless.  \the gives pt with catcode 12.
>
>Donald Arseneau            asnd@reg.triumf.ca

For cases where one wants the text output, rather than simply
the answer. E.g, if numbering axes, one may want

    .25   .50   .75   1.00    1.25   1.50   1.75 ...
		
but using dimension variables gives you floating points, with
occasional rounding errors. E.g., using the method given above,
one gets:

  1 + 2 = 3.0

  1.05 + 2.05 = 3.1

  8.10 + 3.05 = 11.15001


This last example, due to rounding errors inside TeX when converting
between sp and pt, may vary from system to system.


Tim
-- 
Timothy Van Zandt   (609)258-4050  tvz@Princeton.EDU (NeXTMail)
Dept. of Economics,  Princeton University,  Princeton, NJ 08544