How can I extract arrays from a structure?

1 次查看（过去 30 天）
Borja
Borja 2013-5-10
Hi all,
This is my problem:
I load several files using the command 'dir'. Then, I import the data sheet (numbers + headers) with the command 'importdata'. The result is a structure (number of objects imported x 1).
The data are matrices of (602,603 or 604 x 9). I want to extract certain columns of the data sheets and I use a for loop but it gives this error:
Subscripted assignment dimension mismatch.
Error in loading (line 12)
Q(length(vals(i).data(:,7)),i)= vals(i).data(:,7)
Here I attach the piece of code:
clc;clear all;
% Loads the files of the selected directory
loadfiles = dir('*.txt');
% Preallocation of the variable which will contain the data
vals = [];
Q = [];
for i = 1:length(loadfiles)
% Select the "useful" part of the structure (data)
vals = [vals; importdata(loadfiles(i).name)];
% Select the seventh column of each data sheet
Q(length(vals(i).data(:,7)),i)= vals(i).data(:,7)
end
thanks in advance

请先登录，再回答此问题。

回答（2 个）

Alessandro Renna
Alessandro Renna 2013-5-11
编辑：Alessandro Renna 2013-5-11
try to use cell variable for Q as:
Q{length(vals(i).data(:,7)),i}= vals(i).data(:,7)
Cedric
Cedric 2013-5-12
编辑：Cedric 2013-5-12
There is no such thing as vals(i).data.
If you wanted to save only the 7 relevant columns, you could update a little your code as follows:
cId = [1 2 3 4 6 7 9] ; % ID of the 7 relevant columns.
Q = [] ;
for i = 1 : length(loadfiles)
buffer = importdata(loadfiles(i).name) ; % Temporary storage.
Q = [Q; buffer.data(:,cId)] ; % Append only 7 relevant cols.
end

类别

在 Help Center 和 File Exchange 中查找有关 Structures 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