How to combine multiple .txt and calculate Mean, Std, Min, Max

I have several .txt files like this

A .txt=

10 1 4

20 2 5

30 3 6

B.txt

10 7 11

20 8 12

30 9 13

C..txt

10 13 18

20 14 19

30 15 20

D.txt

10 1 4 7 11 13 18

20 2 5 8 12 14 19

30 3 6 9 13 15 20

I want to combine those file into once like in D.txt and plotting the files as first column is y ordinat [10,20,30] and others is x absis.

Then I want to calculate, mean , median, std and get max an min values of my file.

The Result like this

Mean Std Min Max

Y ordinat X absis

10 1 4 7 11 13 18 5 5.883795 -0.8838 10.8838

20 2 5 8 12 14 19 5 5.992058 -0.99206 10.99206

30 3 6 9 13 15 20 5 6.12178 -1.12178 11.12178

Any one can help? I would be appreciate.

Thanks you

Haifani

[Turlough Hughes]

Are you just plugging in random values for mean, std, min, max in your table above? Or how are you planning on calculating them? the max of each row should be 18, 19, 20 respectively.

[Skydriver]

I calculate mean, std with excel and I want to compute in Matlab. The 18 19 and 20 is the values of C.txt in row 3. D,txt is merge files of A.txt, B.txt and C.txt.

[Turlough Hughes]

Can you explain how you get 10.8838, 10.99206 or 11.12178 as your maxima?

[Turlough Hughes]

Ah, ok I see. min and max are the range of your solution from the mean by one standard deviation!

[Skydriver]

Yes. Off course So for developed the figure I only use one column of each as the y ordinat. Yes I also explained about standard deviation. But I still missing how to merge the data as displat in D.txt.

Answer 1

[Turlough Hughes]

Put all your txt files in a folder and you can then use the following

myfolder='name of the folder'
fils=dir([myfolder '\*.txt']); % lists all the files with a .txt extension in myfolder
[~,idx]=sort({fils.name}); % index to load .txt files alphabetically
temp=readmatrix([fils(idx(1)).folder '\' fils(idx(1)).name]); % read A.txt
Y=temp(:,1); X=temp(:,2:end);

for ii=idx(2:end)
    temp=readmatrix([fils(ii).folder '\' fils(ii).name]);
    X=[X temp(:,2:end)];
end
plot(X,Y)

As for your statistics you may need to modify mean and std to suit your needs:

meanD=mean(X,2);    % these are the mean values of each row...
stdD=std(X,0,2);    % standard deviations of each row.
medianD=median(X,2);
minD=meanD-stdD;
maxD=meanD+stdD;
D=table(Y,X,meanD,stdD,medianD,minD,maxD)
writetable(D,'D.txt')

D.txt will be saved in your working directory.

[Skydriver]

Thanks, but I have small problem. When I running with your code, I get small mistake like this:

My coding will be like this:

File={'A.txt','B.txt','C.txt}

or

A=[10 1 4;20 2 5;30 3 6];

B=[10 7 11;20 8 12;30 9 13];

C=[10 13 18;20 14 19;30 15 20];

File={A,B,C};

myfolder='File'

fils=dir([myfolder '\*.txt']); % lists all the files with a .txt extension in myfolder

[~,idx]=sort({fils.name}); % index to load .txt files alphabetically

temp=readmatrix([fils(idx(1)).folder '\' fils(idx(1)).name]); % read A.txt

Y=temp(:,1); X=temp(:,2:end);

for ii=idx(2:end)

temp=readmatrix([fils(ii).folder '\' fils(ii).name]);

X=[X temp(:,2:end)];

end

plot(X,Y)

I got a massage:

Index exceeds matrix dimensions.

temp=readmatrix([fils(idx(1)).folder '\' fils(idx(1)).name]); % read A.txt

[Turlough Hughes]

You need include the full pathname in the variable myfolder, i.e.

myfolder='C:\...\File'

So, in this case you would have your text files A,B,C, etc., located in a folder called File.

[Skydriver]

Do you have another option to read the file?

I try with this :File={'A.txt','B.txt','C.txt}

Because with this code give a massage:

Reference to non-existent field 'folder'.

Error in CalcAll (line 50)

temp=readmatrix([fils(idx(1)).folder '\' fils(idx(1)).name]); % read A.txt

[Turlough Hughes]

Yea, I wrote the above to allow flexibility in the number of files being loaded in, but you can also place the files in your working directory and load them in as follows:

A=readmatrix('A.txt');
B=readmatrix('B.txt');
C=readmatrix('C.txt');
X=[A(:,2:end) B(:,2:end) C(:,2:end)];
Y=A(:,1);  
plot(X,Y)

[Skydriver]

Nice its works know I change readmatrix with importdata. I use Matab2018a.

Thank you

Akhmad