Path: utzoo!attcan!uunet!husc6!mailrus!uflorida!novavax!hcx1!hcx2!dougs
From: dougs@hcx2.SSD.HARRIS.COM
Newsgroups: comp.lang.misc
Subject: Re: Row/Column Major Definition and His
Message-ID: <44600002@hcx2>
Date: 6 Sep 88 12:31:00 GMT
References: <16512@apple.Apple.COM>
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Nf-ID: #R:apple.Apple.COM:16512:hcx2:44600002:000:860
Nf-From: hcx2.SSD.HARRIS.COM!dougs    Sep  6 08:31:00 1988




Row and/or column major refers to the way the arrays are stored in memory.
This is only relevant for 2D or greater dimensioned arrays.  Row major
means that as you move through *sequentially addressed* memory locations,
the right-most subscript of an array reference will increase fastest.  Column
major means the left-most subscript varies fastest.

When you dealt with graphs or arrays in school, the most usual way for you
to envision them was probably row-major.
	
	a(1,1..4)   5 6 7 8
        a(2,1..4)   6 1 8 0
        a(3,1..4)   2 8 4 7
          ...

It is interesting to note that almost all languages have array accessing
defined as row-major (C, Pascal, blah-blah-blah) but FORTRAN is column
major.  Why? ....

Douglas G. Scofield				dougs@hcx2.ssd.harris.com
Harris Computer Systems Division
2101 W. Cypress Creek Rd.
Ft. Lauderdale, FL  33069