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From: roz@l.cc.purdue.edu (Vu Qui Hao-Nhien)
Newsgroups: sci.math
Subject: Re: Algorithm Description
Message-ID: <460@l.cc.purdue.edu>
Date: Tue, 18-Nov-86 16:11:29 EST
Article-I.D.: l.460
Posted: Tue Nov 18 16:11:29 1986
Date-Received: Wed, 19-Nov-86 06:19:31 EST
References: <146@helm.UUCP> <9700056@uiucdcsb> <1266@megaron.UUCP>
Reply-To: roz@l.cc.purdue.edu.UUCP (Vu Qui Hao-Nhien)
Distribution: world
Organization: Purdue U. Dept. of Mathematics
Lines: 42
Keywords: "repeat"

Expiration:

In article <1266@megaron.UUCP> johnk@megaron.UUCP writes:
Essentialy, that 'the ghastly "step 1", "step 2", "go to >step i" style' is,
well, ghastly.  And then gave the alternative for a goto:
>
>	repeat {
>		v1 = 2*rand() - 1
>		v2 = 2*rand() - 1
>		s = v1^2 + v2^2
>	} until ( s < 1 )
>	x1 = v1 * sqrt(-2 * ln(s) / s)
>	x2 = v2 * sqrt(-2 * ln(s) / s)

Well, goto looks a whole lot more formal.  I don't know why.  It just feels
that way.  My own style is instead of using brackets {}, I'd do

	step 1.
		v1 = ....
		v2 = ....
	step 2. if s >= 1, repeat Big step 1.
	step 3. x1 = ....
		x2 = ....

Brackets, especially when written your way, is intimidating (eg.  Why
is there a right bracket at the beginning of a line ? )

>I think the computer scientist most
>mathematicians know of is Knuth, and by presenting the algorithms of his
>_The_Art_of_Computer_Programming_ in the numbered step form, he legitimized
>a style which should, in our enlightened age, be obsolete.

Sad but true.  Most mathematicians present algorithms the Knuth way, mostly
because they learn basic mathematical algorithms from Knuth's book.

===========
Hao-Nhien Q. Vu (pur-ee!stat-l!vu)
                (vu@l.cc.purdue.edu)
[That's stat-"ell", not stat-"one"]

-- 
Hao-Nhien Q. Vu (pur-ee!stat-l!vu)
                (vu@l.cc.purdue.edu)
[That's stat-"ell", not stat-"one"]