[Fwd: [OctDev] slow structs]

[Daniel J Sebald]

-------- Original Message --------
Subject: [OctDev] slow structs
Date: Wed, 17 Dec 2008 18:13:17 -0600
From: Jonathan Kotta <address@hidden>
To: address@hidden

I have a problem where a vector within a struct is much slower to
index than a plain vector (~8x slower) .

x = zeros(1e6,1);
s.x = x;
subset = 500e3:600e3-1;
y = randn(length(subset),1);
for i = 1:5
  tic; x(subset) = y; toc;
end
for i = 1:5
  tic; s.x(subset) = y; toc;
end
tic;
for i = 1:100
  x(subset) = y;
end
toc;
tic;
for i = 1:100
  s.x(subset) = y;
end
toc;

Tested using Octave 3.0.3 on x86-64.

--
Thanks,

Jonathan Kotta

Hofstadter's Law:
   It always takes longer than you expect, even
   when you take into account Hofstadter's Law.

------------------------------------------------------------------------------
SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada.
The future of the web can't happen without you.  Join us at MIX09 to help
pave the way to the Next Web now. Learn more and register at
http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/
_______________________________________________
Octave-dev mailing list
address@hidden
https://lists.sourceforge.net/lists/listinfo/octave-dev


--

Dan Sebald
email: daniel(DOT)sebald(AT)ieee(DOT)org
URL: http://www(DOT)dansebald(DOT)com