Organising data into new matrix nxp

3 次查看（过去 30 天）
scour_man
scour_man 2011-7-8
Hi! I have several matrices (Z1, Z2, Z3 etc.) all of which are 322x202 and are values of depths from seabed surveys (each depth value within a matrix is for a different position). All surveys cover an identical area but are from different times (months/years apart). There are corresponding matrices X and Y which hold the latitude and longitude positions allowing visualisation of data by contour plot etc.
What I would like to do (in order for some statistical analysis) is rearrange the data into one matrix nxp where n is the number of timesteps and p is the positions.
I understand how to do this for very small matrices by matrix indexing but this is extremely tedious and time consuming... how can I do it quickly for my large matrices?
Any help much appreciated

请先登录，再回答此问题。

采纳的回答

the cyclist
the cyclist 2011-7-8
The fact that your original Zn matrices are named like that makes things a bit awkward. You might want to read this:
http://www.mathworks.com/matlabcentral/answers/143-how-do-i-make-a-series-of-variables-a1-a2-a3-a10
to learn ways to avoid that, if possible.
However, if you are stuck with those variable names, then you can do something like the following:
N = 2; % Number of individual Z arrays (i.e. time steps)
Z1 = rand(3,4);
Z2 = rand(3,4);
% Get all the individual Z arrays into one big one
Z = zeros(3,4,N);
for i = 1:N
eval(['Z(:,:,i)=Z',num2str(i)]);
end
% Permute so that the time dimension is the first dimension
Z_time_first = permute(Z,[3 1 2]);
% Reshape so that the array is (number time steps X number observations)
Z_time_by_observations = reshape(Z,[2,12]);
I am not 100% sure this is what you meant, but I hope it has all the components you need to do what you want.
  2 个评论
Oleg Komarov
Oleg Komarov 2011-7-8
I really recommend to store your Z1,Z2...as Z(:,:,1:n) since the beginning, if you can intervene in that part of the cycle.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Resizing and Reshaping Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by