forum.alglib.net

ALGLIB forum
It is currently Sun Dec 22, 2024 2:13 pm

All times are UTC


Forum rules


1. This forum can be used for discussion of both ALGLIB-related and general numerical analysis questions
2. This forum is English-only - postings in other languages will be removed.



Post new topic Reply to topic  [ 2 posts ] 
Author Message
 Post subject: what is purpose of stride in arrays?
PostPosted: Fri Feb 04, 2011 5:57 pm 
Offline

Joined: Mon Nov 15, 2010 11:16 am
Posts: 1
Hello, first of all just like to say that this is a great library. I'm just starting and it is very nice to have this

I was trying to use vadd on real_2d_array datatypes and saw that it was not working correctly, but I realized that it was because I was not entering the "strides" as an input and the default stride is 1 when my arrays had strides of 2.

what is the purpose of this stride?


Top
 Profile  
 
 Post subject: Re: what is purpose of stride in arrays?
PostPosted: Fri Feb 04, 2011 8:52 pm 
Offline
Site Admin

Joined: Fri May 07, 2010 7:06 am
Posts: 927
There are two meanings of "stride". First, stride is used to align array rows on 16-byte boundary. It is necessary for better caching control, for better utilization of SSE2 intrinsics - for better performance, in two words.

Second, when we talk about Level 1 BLAS functions, stride is a distance between consecutive elements of vector (row/column). When it is 1, we have vector or row. When you want to work with columns of a matrix, stride is greater than 1.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 38 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group