Creating matrix from a loop between multiple files

Question

Ben Bawtree 2022-3-18

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1674679-creating-matrix-from-a-loop-between-multiple-files

评论： Ben Bawtree 2022-3-18

Hi! I am currently trying to format a code which runs through the same steps but for multiple different files which have been loaded into the data base. I am unsure as to how to compress it into a some sort of loop if that'd quicken it? This is the first set of code which I want to condense and obtain the outputs RS1, RS2 and RS3 in a matrix.

% Repeat process by calling and averaging the wanted columns in data file 'c1'.
uc1 = c1(:,3);
u1c1 = [mean(uc1) mean(uc1)];
wc1 = c1(:,5);
u3c1 = [mean(wc1) mean(wc1)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_1 = uc1-u1c1;
upr3_1 = wc1-u3c1;
% Compute the product of both deviations
uval1 = upr1_1.*upr3_1;
uva_1 = [mean(uval1) mean(uval1)];
RS1 = uva_1(1,2)/(10e-5);
% Repeat process by calling and averaging the wanted columns in data file 'c2'.
uc2 = c2(:,3);
u1c2 = [mean(uc2) mean(uc2)];
wc2 = c2(:,5);
u3c2 = [mean(wc2) mean(wc2)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_2 = uc2-u1c2;
upr3_2 = wc2-u3c2;
% Compute the product of both deviations
uval2 = upr1_2.*upr3_2;
uva_2 = [mean(uval2) mean(uval2)];
RS2 = uva_2(1,2)/(10e-5);
% Repeat process by calling and averaging the wanted columns in data file 'c3'.
uc3 = c3(:,3);
u1c3 = [mean(uc3) mean(uc3)];
wc3 = c3(:,5);
u3c3 = [mean(wc3) mean(wc3)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_3 = uc3-u1c3;
upr3_3 = wc3-u3c3;
% Compute the product of both deviations
uval3 = upr1_3.*upr3_3;
uva_3 = [mean(uval3) mean(uval3)];
RS3 = uva_3(1,2)/(10e-5);

Then this is another set, which I also want to loop and form a matrix of umc1:5 values.

%C1 @ 0.45m 
uc1 = c1(:,3);
umc1 = mean(uc1);
%C2 @ 0.40m 
uc2 = c2(:,3);
umc2 = mean(uc2);
%C3 @ 0.35m 
uc3 = c3(:,3);
umc3 = mean(uc3);
%C4 @ 0.30m
uc4 = c4(:,3);
umc4 = mean(uc4);
%C5 @ 0.25m  
uc5 = c5(:,3);
umc5 = mean(uc5);

Any help would be greatly appreciated, many thanks. Ben

4 个评论
显示 2更早的评论隐藏 2更早的评论

Jan 2022-3-18

编辑：Jan 2022-3-18

This comment does not increase the clarity. You want to modify the code to expand it from using one fileto using a bunch of files. Then the actual computations do not matter, but how you imprt the file. This means, that the posted code is not relecant to the question, but the important code is missing.

Ben Bawtree 2022-3-18

在 MATLAB Online 中打开

Load ('c1.dat')
Load ('c2.dat')
Load ('c3.dat')
% Repeat process by calling and averaging the wanted columns in data file 'c1'.
uc1 = c1(:,3);
u1c1 = [mean(uc1) mean(uc1)];
wc1 = c1(:,5);
u3c1 = [mean(wc1) mean(wc1)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_1 = uc1-u1c1;
upr3_1 = wc1-u3c1;
% Compute the product of both deviations
uval1 = upr1_1.*upr3_1;
uva_1 = [mean(uval1) mean(uval1)];
RS1 = uva_1(1,2)/(10e-5);
% Repeat process by calling and averaging the wanted columns in data file 'c2'.
uc2 = c2(:,3);
u1c2 = [mean(uc2) mean(uc2)];
wc2 = c2(:,5);
u3c2 = [mean(wc2) mean(wc2)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_2 = uc2-u1c2;
upr3_2 = wc2-u3c2;
% Compute the product of both deviations
uval2 = upr1_2.*upr3_2;
uva_2 = [mean(uval2) mean(uval2)];
RS2 = uva_2(1,2)/(10e-5);
% Repeat process by calling and averaging the wanted columns in data file 'c3'.
uc3 = c3(:,3);
u1c3 = [mean(uc3) mean(uc3)];
wc3 = c3(:,5);
u3c3 = [mean(wc3) mean(wc3)];
% Calculate standard deviation from the mean for u1 and u3. 
upr1_3 = uc3-u1c3;
upr3_3 = wc3-u3c3;
% Compute the product of both deviations
uval3 = upr1_3.*upr3_3;
uva_3 = [mean(uval3) mean(uval3)];
RS3 = uva_3(1,2)/(10e-5);

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Stephen23 2022-3-18

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1674679-creating-matrix-from-a-loop-between-multiple-files#answer_921029

编辑：Stephen23 2022-3-18

在 MATLAB Online 中打开

Use arrays and indexing rather than numbered variable names.

Use a more appropriate tool for importing textfile data, e.g. READMATRIX

P = 'absolute or relative path to where the files are saved';
V = 1:3;
RSV = nan(size(V));
for k = 1:numel(V)
    F = sprintf('c%u.dat',V(k));
    c1 = readmatrix(fullfile(P,F));
    uc1 = c1(:,3);
    u1c1 = [mean(uc1),mean(uc1)];
    wc1 = c1(:,5);
    u3c1 = [mean(wc1),mean(wc1)];
    % Calculate standard deviation from the mean for u1 and u3. 
    upr1_1 = uc1-u1c1;
    upr3_1 = wc1-u3c1;
    % Compute the product of both deviations
    uval1 = upr1_1.*upr3_1;
    uva_1 = [mean(uval1),mean(uval1)];
    RSV(k) = uva_1(1,2)/(10e-5);
end