help-octave
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Extracting segents of data from array


From: Jordi Gutiérrez Hermoso
Subject: Re: Extracting segents of data from array
Date: Mon, 3 Jan 2011 12:31:59 -0600

On 3 January 2011 12:13, lciotti <address@hidden> wrote:

> I have a large array that I want to extract specific rows from.

Octave doesn't really have arrays... I mean, internally it does, but
the basic data type exposed at the interpreter is a matrix. It makes a
subtle difference. For example, matrices don't nest like arrays do, a
matrix cannot contain another matrix, at least not in the same way
that an array can contain or point to other arrays. An array is
usually immutable in size (at least, that's how C and C++ interpret
the word "array") but Octave matrices are highly mutable in size and
shape.

I say these things as a warning lest you take the comparison between
array and matrix too far. I have seen people do this and be surprised
when [[["h"],["e"]],[[["llo"]]]] == "hello", for example.

I see Ben has given you a solution for the rest of your question as I
was writing this, so I'll omit the rest of the response I was
preparing.

- Jordi G. H.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]