Date:         Wed, 23 Nov 2011 16:09:10 -0800
Reply-To:     Mark Miller <mdhmiller@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Mark Miller <mdhmiller@GMAIL.COM>
Subject:      Re: How SAS compresses this obervation
Comments: To: bbser 2009 <bbser2009@gmail.com>
In-Reply-To:  <000001ccaa29$b7338610$259a9230$@com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Max,

I doubt the file would look anything like that.
Compress=CHAR uses an algorithm called RDC
"Ross Data Compression" published in
'The C Users Journal", Vol 10, No. 10, October 1992
This is an adaptive compression  algorithm which uses several
sub-algorithms including Run Length Encoding (RLE)

You can retrieve the C source code from
     http://drdobbs.com/184402606

A description of the algorithm can be found at
http://www.amiga-stuff.com/text/crunchers/RDCN.txt

A Pascal port of the original C program can be found at

http://www.howtodothings.com/computers/a1216-ross-data-compression.html

... mark

On 11/23/2011 1:49 PM, bbser 2009 wrote:
> Does anyone have any idea about this thread? Thanks.
>
> -----Original Message-----
> From: bbser 2009 [mailto:bbser2009@gmail.com]
> Sent: November-23-11 1:20 AM
> To: 'SAS-L@LISTSERV.UGA.EDU'
> Subject: How SAS compresses this obervation
>
> Greetings!
>
> Assuming the lengths of both Lastname and Firstname are 10 bytes.
> If Lastname='Smith' and Firstname='Tom', then do you think, in the
> compressed file generated by using compressed=CHAR, the observation looks
> something like this?
>
> 5 S m i t h 5 3 T o m 7
>
> Thank you.
>
> Regards, Max
> (Maaxx)