Drexel dragonThe Math ForumDonate to the Math Forum


Math Forum
 Ask Dr. Math
 Discussions
 Internet Newsletter
 MathTools
 Problems of the Week
 Teacher2Teacher
 Teacher Exchange
 Workshops

Search All of the Math Forum:
Browse our Internet Mathematics Library

Views expressed in these public forums are not endorsed by Drexel University or The Math Forum.


Math Forum » Discussions » Software » comp.soft-sys.math.mathematica

Topic: Compile function and AppendTo for lists (vrs. 8.0.4)
Replies: 8   Last Post: Feb 1, 2012 3:50 AM

Advanced Search
Reply to this Topic Reply to this Topic

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
Patrick Scheibe

Posts: 327
Registered: 5/22/07
Re: Compile function and AppendTo for lists (vrs. 8.0.4)
Posted: Jan 31, 2012 5:43 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

Hi Fred,

some short notes:


> appendBag2a = Compile[{{k, _Integer, 0}}, Module[{p = Bag[Most[{0}]]},
> Do[StuffBag[p, Bag[{1, i}]], {i, 1, k}];
> Table[BagPart[BagPart[p, i], All], {i, 1, k}]]];
>
> That works fine and fast,

But look that your type p is clearly wrong. p is a bag of bags of
Integer and has to be initialized with

Internal`Bag[Most[{Internal`Bag[{1}]}]]

We can only guess about the reasons why it works anyway. If it is
implemented with pointers, than it seems the integers of your p-Bag are
used to store the pointers.

> The problem seems to be the initialization of the
> locale variable p. I tried compilation with the definitions p=Bag[],
> p=Bag[{}], p=Bag[Rest[{0}]], p=Bag[Rest[{{0,0}}]], or e.g.

Now you know how.

Cheers
Patrick

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© Drexel University 1994-2013. All Rights Reserved.
The Math Forum is a research and educational enterprise of the Drexel University School of Education.