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## Re: 2D matrixes into a 3D matrix

**From**: |
Andres Sepulveda |

**Subject**: |
Re: 2D matrixes into a 3D matrix |

**Date**: |
Mon, 29 Jan 2007 19:49:48 -0300 (CLST) |

**User-agent**: |
SquirrelMail/1.4.4 |

Hi, sorry for the brief description.
I have 2D fields of sea surface tempereature, say 50x40, and I want to
put them in a 3D array, where the third index is time. The idea is to be
able to add more and more 2D fields for which I need a way to increase
the size of it from
(50x40x2) to (50x40x3) or (50x40x15), depending on data availability
is there a clever way to do this?
Andres
On Mon, January 29, 2007 5:39 pm, David Bateman said:
>* Andres Sepulveda wrote:*
>*> Hi,*
>*>*
>*> I want to "stick" a series of 2D (e.g. 2x2) matrixes into a 3D matrix*
>*> (2x2xN) with N increasing as I stick a new matrix.*
>*>*
>*> Is it better to define a large-enough 3D matrix and then reduce its*
>*> size?*
>*>*
>*> Andres*
>*>>*
>
>* I have no idea what you mean from the above statement. If you know the*
>* final size of the 3D matrix, then yes it is better to preallocate the*
>* memory something like*
>
>
>* A = zeros([2,2,N]);*
>* for i=1:N*
>* A(:,:,i)= randn(2,2);*
>* endfor*
>
>
>* is definitely an advantage, though the above example is artificial and*
>* should be written as A = randn([2,2,2]) instead. Note that is you can*
>* vector the code as do without the loop to create the matrix, you are*
>* much better off without it...*
>
>* D.*
>