Working with a three dimensional matrix

2011 1 24
2 个回答
回答已采纳
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1 个投票

I have a matrix with three dimensions, and I need to take two dimensions through the use of cycle FOR.
For example:
Name variable Value
k <39x17x60>
And I need this:
a = 60;
for i = 1:60;
l = k...; %size of l <39x17>
xlswrite...;
end

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 采纳的回答

Oleg Komarov
Oleg Komarov 2011-1-25

0 个投票

The problem is how you construct kunn, in general there are so many nested loops that my suspect is you end up overwriting the data, go in debug mode and see what happens each time you increase the frist loop and so on:
function[F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax,Emin,Emax_min,Estd,Emedian,TEO,Jmean,...
Jmax,Jmin,Jmax_min,Jstd,Jmedian,Smean,Smax,Smin,...
Smax_min,Sstd,Smedian,F1mean,F1max,F1min,F1max_min,F1std,...
F1median,F2mean,F2max,F2min,F2max_min,F2std,F2median]...
= HRA()
[wav,lab]=databaze;
wav = wav';
lab = lab';
L = length(wav);
for j = 2:L+1
brd = process_lab_file(lab{j-1});
label = brd(:,1);
K = length(label);
for i = 1:K
[F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax, Emin,Emax_min, Estd, Emedian, TEO,...
Jmean,Jmax,Jmin,Jmax_min,Jstd,Jmedian,...
Smean,Smax,Smin,Smax_min,Sstd,Smedian,...
F1mean,F1max,F1min,F1max_min,F1std,F1median,...
F2mean,F2max,F2min,F2max_min,F2std,F2median]=extr_part_of_sig(wav{j-1},label(i),lab{j-1});
priznaky =...
[F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax, Emin,Emax_min, Estd, Emedian, TEO,...
Jmean,Jmax,Jmin,Jmax_min,Jstd,Jmedian,...
Smean,Smax,Smin,Smax_min,Sstd,Smedian,...
F1mean,F1max,F1min,F1max_min,F1std,F1median,...
F2mean,F2max,F2min,F2max_min,F2std,F2median];
O = length(priznaky);
for o = 1:O
zap(o,i) = priznaky(o);
end
end
F = length(priznaky);
for i = 1:K
for a = 1:F
kunn(a,j-1,i) = zap(a);
end
end
end
S = length(label);
jaj = zeros(39,17);
for f = 1:S
jaj = kunn(:,:,2);
koj = jaj';
%xlswrite('ZK.xls', koj, label{i}, 'B2');
end

1 个评论
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Pepa
Pepa 2011-1-25
In debug I found error. You have right. Matrix in kunn is same...

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更多回答（1 个）

Kenneth Eaton
Kenneth Eaton 2011-1-24

1 个投票

If you're asking how you would index k in your loop to get a 2-D submatrix, you would do the following:
l = k(:,:,i);

14 个评论
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Paulo Silva
Paulo Silva 2011-1-24
I wasn't fast enough, you posted first :)
% k <39x17x60>
k=randn(39,17,60); %example data
%And I need this:
l=zeros(39,17); %preallocation of l
for i = 1:60
l=k(:,:,i); %size of l <39x17>
%xlswrite...;
end
Pepa
Pepa 2011-1-25
In your case it works, but in my case it doesn't work, but i don't know why.
S = length(label);
jaj = zeros(39,17);
for f = 1:S
jaj = kunn(:,:,f);
koj = jaj';
%xlswrite('ZK.xls', koj, label{i}, 'B2');
end
Paulo Silva
Paulo Silva 2011-1-25
please explain exactly what doesn't work in your simple code?
Pepa
Pepa 2011-1-25
I don't know where is the problem. But it does't work how i expected.
If i changed code:
jaj = kunn(:,:,2); (or diferent number it does't matter and in variable jaj is first matrix (39x17))
Screenshot of variables:
http://img153.imageshack.us/i/89568725.gif/
http://img829.imageshack.us/i/72979235.gif/
Kenneth Eaton
Kenneth Eaton 2011-1-25
Pepa, I'm still not clear on exactly what error/problem you are having when you run your code. The two screenshots of the variables look fine. Note that kunn(:,:,1) and jaj are the same, there is just a scaling factor of 1.0e+003 used to display kunn.
Pepa
Pepa 2011-1-25
My problem is that if i put in kunn(:,:,X) X = 1,2,...n, In jaj is still kunn(:,:,1).
Walter Roberson
Walter Roberson 2011-1-25
By the way, preallocation of jaj is not needed as you are overwritten its complete contents each trip through the loop.
Walter Roberson
Walter Roberson 2011-1-25
Pepa, put in kunn(:,:,X) *where* ?? Code example, please.
Pepa
Pepa 2011-1-25
Whole code of function:
function [F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax, Emin,Emax_min, Estd, Emedian, TEO,...
Jmean,Jmax,Jmin,Jmax_min,Jstd,Jmedian,...
Smean,Smax,Smin,Smax_min,Sstd,Smedian,...
F1mean,F1max,F1min,F1max_min,F1std,F1median,...
F2mean,F2max,F2min,F2max_min,F2std,F2median] = HRA ()
[wav,lab]=databaze;
wav = wav';
lab = lab';
L = length(wav);
for j = 2:L+1
brd = process_lab_file(lab{j-1});
label = brd(:,1);
K = length(label);
for i = 1:K
[F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax, Emin,Emax_min, Estd, Emedian, TEO,...
Jmean,Jmax,Jmin,Jmax_min,Jstd,Jmedian,...
Smean,Smax,Smin,Smax_min,Sstd,Smedian,...
F1mean,F1max,F1min,F1max_min,F1std,F1median,...
F2mean,F2max,F2min,F2max_min,F2std,F2median]=extr_part_of_sig(wav{j-1},label(i),lab{j-1});
priznaky = [F0mean,F0max,F0min,F0max_min,F0std,F0median,relF0VR,relF0SD,...
Emean,Emax, Emin,Emax_min, Estd, Emedian, TEO,...
Jmean,Jmax,Jmin,Jmax_min,Jstd,Jmedian,...
Smean,Smax,Smin,Smax_min,Sstd,Smedian,...
F1mean,F1max,F1min,F1max_min,F1std,F1median,...
F2mean,F2max,F2min,F2max_min,F2std,F2median];
O = length(priznaky);
for o = 1:O
zap(o,i) = priznaky(o);
end
end
F = length(priznaky);
for i = 1:K
for a = 1:F
kunn(a,j-1,i) = zap(a);
end
end
end
S = length(label);
jaj = zeros(39,17);
for f = 1:S
jaj = kunn(:,:,2); % PROBLEM IS HERE
koj = jaj';
%xlswrite('ZK.xls', koj, label{i}, 'B2');
end
Oleg Komarov
Oleg Komarov 2011-1-25
Why don't you apply what Kenneth suggested (not to mention Walter):
jaj = kunn(:,:,s)
And what's the problem, btw, can you elaborate, post any error message or unwanted result?
Pepa
Pepa 2011-1-25
It does't work, I applied this jaj=kunn(:,:,s).I don't know why. No error, just in the jaj is still only first matrix.
Pepa
Pepa 2011-1-25
I can use every number on position 's' and result is always same and this is first matrix...
Oleg Komarov
Oleg Komarov 2011-1-25
isequal(kunn(:,:,1),kunn(:,:,2)) should be 0, can you confirm?
Pepa
Pepa 2011-1-25
No i can't. isequal(kunn(:,:,1),kunn(:,:,2)) result is logical 1. And this is my problem.

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