How to save each loop data

7 次查看（过去 30 天）
Chuanjung Lin
Chuanjung Lin 2019-10-22
评论： Chuanjung Lin 2019-10-30
Hi all,
I have a batch file need to input to workspace for analysis, and the file type is *.csv.
Following is the code that I used, and the output file only show thw last one "P"
I hope each input file cas save as P1, P2, P3,....
May I know how to modify it ? thank you.
%% Open file dir
[filename,filedir] = uigetfile('*.csv','Multiselect','on');
path = fullfile(filedir,filename);
path = path';
file = struct('name',path);
%% Cover struc to cell
c= struct2cell(file);
opts = delimitedTextImportOptions("NumVariables", 9);
% Specify range and delimiter
opts.DataLines = [3, Inf];
opts.Delimiter = [" ", ","];
% Specify column names and types
opts.VariableNames = ["V", "I1V", "I2V", "I3V", "I4V", "I5V", "I6V", "I7V", "I8V"];
opts.VariableTypes = ["double", "double", "double", "double", "double", "double", "double", "double", "double"];
opts.ExtraColumnsRule = "ignore";
opts.EmptyLineRule = "read";
%% Readtable Import the data
for i=1:length(file)
P = table2array(readtable(c{i}, opts));
end
  1 个评论
Stephen23
Stephen23 2019-10-22
编辑：Stephen23 2019-10-22
"I hope each input file cas save as P1, P2, P3,...."
Don't do that. Read this to know why:
https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval
You should use indexing, just like the MATLAB documentation shows:
https://www.mathworks.com/help/matlab/import_export/process-a-sequence-of-files.html
Indexing is simple, easy to debug, and very efficient (unlike what you are trying to do).

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Subhadeep Koley
Subhadeep Koley 2019-10-29
You defined P as a single variable, therefore it is holding only the last value of the loop. If you want to want to save each loop data to a separate variable, the following code might help you.
Just declare P as an empty cell array and access P using the indexing variable i in every loop.
%% Open file dir
[filename,filedir] = uigetfile('*.csv','Multiselect','on');
path = fullfile(filedir,filename);
path = path';
file = struct('name',path);
%% Cover struc to cell
c= struct2cell(file);
opts = delimitedTextImportOptions("NumVariables", 9);
% Specify range and delimiter
opts.DataLines = [3, Inf];
opts.Delimiter = [" ", ","];
% Specify column names and types
opts.VariableNames = ["V", "I1V", "I2V", "I3V", "I4V", "I5V", "I6V", "I7V", "I8V"];
opts.VariableTypes = ["double", "double", "double", "double", "double", "double", "double", "double", "double"];
opts.ExtraColumnsRule = "ignore";
opts.EmptyLineRule = "read";
% Declare empty cell array P
P = {};
%% Readtable Import the data
for i=1:length(file)
P{i} = table2array(readtable(c{i}, opts));
end
Hope this helps!
  2 个评论
Stephen23
Stephen23 2019-10-29
+1 tidy answer.
Using path as a variable name should be avoided, as this shadows the inbuilt path function.
Chuanjung Lin
Chuanjung Lin 2019-10-30
Thank you for your help^_^!

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 File Operations 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