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
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
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
A description of the algorithm can be found at
A Pascal port of the original C program can be found at
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:email@example.com]
> Sent: November-23-11 1:20 AM
> To: 'SAS-L@LISTSERV.UGA.EDU'
> Subject: How SAS compresses this obervation
> 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