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From: cloos@acsu.buffalo.edu (James H. Cloos)
Newsgroups: comp.sys.handhelds
Subject: Re: DEC2FRAC-II for the HP48SX
Message-ID: <68046@eerie.acsu.Buffalo.EDU>
Date: 31 Mar 91 22:50:39 GMT
References: <12222 <1991Mar30.191031.26274@en.ecn.purdue.edu> <14476@life.ai.mit.edu>
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In article <14476@life.ai.mit.edu> bson@rice-chex.ai.mit.edu (Jan Brittenson) writes:
|In a posting of [30 Mar 91 19:10:31 GMT]
|   wscott@en.ecn.purdue.edu (Wayne H Scott) writes:
|
| > This program handles:
| >	real numbers
| >	complex numbers
| >	equations
| >	TAGGED objects
| >	lists
| >	and any combination of the above
|
|So all we have to do now, is:
|
|	1. Rewrite Wayne's and Joe's programs in system RPL.
|
|	2. Write +, -, INV, SIN, etc, functions to
|	   replace the keyboard equivalents. Basically, they
|	   should check to see whether one of their arguments
|	   is an algebraic - if not, just chain to the standard
|	   function. Otherwise, we apply the standard operator,
|	   EVAL, and DO->Q.
|
|	3. Appropriate system flag -54, conveniently among
|	   the "Display Format Flags" to mean "fractional
|	   display." If the flag isn't set, just do the
|	   standard old thing, regardless of arguments.
|
|	4. Write a vectored ENTER function to automatically
|	   DO->Q on all input, if flag -54 is set, otherwise
|	   it should do nothing.
|
|	5. Get the "maximum denominator" parameter from a
|	   'FRACpar' variable instead of the stack.
|
|	6. Add code to handle fractional units imposed by the
|	   brain damage of the English unit system - Joe's
|	   wish list seems like a good starting point.
|
|	7. Package it all in a library.
|
|   Voila' - we have an exceptionally useful fractional library.
|Perhaps the most useful one ever put in a calculator? I think just
|using a "display format" is the way to go, rather than trying to
|implement fractions symbolically.
|
|						-- Jan Brittenson
|						   bson@ai.mit.edu

Thanks Jan.  I couldn't have said it better myself!

-JimC
--
James H. Cloos, Jr.		Phone:  +1 716 673-1250
cloos@ACSU.Buffalo.EDU		Snail:  PersonalZipCode:  14048-0772, USA
cloos@ub.UUCP			Quote:  <>