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.matlab

Topic: How to a 1-D matrix into several 1-D matrix based on condition
Replies: 5   Last Post: Dec 8, 2012 4:36 PM

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 ]
dpb

Posts: 6,677
Registered: 6/7/07
Re: How to a 1-D matrix into several 1-D matrix based on condition
Posted: Dec 8, 2012 4:05 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

On 12/8/2012 3:02 PM, james bejon wrote:
> Can't test this, but if you want a vectorized version:
>
> A = [1 3 5 7 8 1 4 0 1 4 6 3 0 0 1 4 6 0 0 0 2 5 9 1].';
> Z = find(A == 0);
> Z = Z(diff([0; Z]) ~= 1);
> S = zeros(length(A), 1);
> S(Z) = 1;
> S = cumsum(S)+1;
> X = accumarray(S, A, [], @(x) {x})

Yeah, probably...but my version here predates accumarray() which sorta'
kills many things similar to OP's problem w/o a loop...or requires so
much other stuff as workaround as to make the loop "more better" in the
end...

I've not looked to see if Bruno or somebody did a FEX submittal...

--

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.