Path: utzoo!utgpu!watmath!clyde!att!rutgers!mailrus!ames!amdahl!nsc!taux01!taux02!amos
From: amos@taux02.UUCP (Amos Shapir)
Newsgroups: comp.arch
Subject: Re: Professional Programmers (was: Seeing the future)
Message-ID: <331@taux02.UUCP>
Date: 3 Dec 88 11:40:56 GMT
References: <1984@eos.UUCP> <28200245@mcdurb> <321@taux02.UUCP> <32353@think.UUCP>
Organization: National Semiconductor (IC) Ltd, Israel Home of the 32532
Lines: 21
Hdate: 24 Kislev 5749

In article <32353@think.UUCP> you write:
>In article <321@taux02.UUCP> amos@taux02.UUCP (Amos Shapir) writes:
>>Most of what a professional programmer does when helping scientists,
>>is to change things like  cos(atan(x))**2  to  1/(1+x*x) .
>
>What does this have to do with being a professional PROGRAMMER?  The
>above identity is a MATHEMATICAL fact, having nothing to do with
>computers, except insofar as the above statements in a program
>approximate the corresponding mathematical operations.

This is exactly the point I was trying to make - to a mathematician,
these two expressions are identical and interchangeable; to a programmer,
one is an expression requiring two function calls (twice if your compiler
is lousy) involving hundreds of operations, while the other requires just 
one multiply and one divide. It's the programmer's job to know these
facts and use them.
-- 
	Amos Shapir				amos@nsc.com
National Semiconductor (Israel) P.O.B. 3007, Herzlia 46104, Israel
Tel. +972 52 522261  TWX: 33691, fax: +972-52-558322
34 48 E / 32 10 N			(My other cpu is a NS32532)