How would I take the mean of each row from column_13 of 79 csv files?

Hi,

I am completely stuck here. I am trying to take the mean of each row of column 13 in the 79 csv files and there are 48 rows in total in each file but I am struggling to make a code here. I anyone can help.

Code tried so far:

close all; clear all; clc;

P = 'F:\3-PIV_Experimental_Data\Calculations_TurbulentIntensity\line_Data\Elliptical_Side_LSB\Length\DesignPoint\110_outlet';
S = dir(fullfile(P,'*.csv'));
N = natsortfiles({S.name});
TurbulentFluctuationArray_Mean=zeros(numel(N), 1);

for i = 1:numel(N);
    data = readtable( fullfile(P, N{i}) ); % read the csv files
    col_13(i) = mean([data(:,13)])
end

Error:

Error using sum

Invalid data type. First argument must be numeric or logical.

Error in mean (line 127)

y = sum(x, dim, flag) ./ mysize(x,dim);

Error in rowMean_practise (line 10)

col_13(i) = mean([data(:,13)],79)

[Karim]

cn you add one of the files as an example?

[muhammad choudhry]

here are 2 of them and I have 79 0f them.

Answer 1

[Karim]

You were almost there, you just need to convert the table to an array to take the mean of the values, see below for a quick fix:

P = 'F:\3-PIV_Experimental_Data\Calculations_TurbulentIntensity\line_Data\Elliptical_Side_LSB\Length\DesignPoint\110_outlet';
S = dir(fullfile(P,'*.csv'));
N = natsortfiles({S.name});
TurbulentFluctuationArray_Mean=zeros(numel(N), 1);

col_13_data = zeros(48,numel(N))

for i = 1:numel(N);
    data = readtable( fullfile(P, N{i}) ); % read the csv files
    col_13_data(:,i) = table2array( data(:,13) ); %  get the 13th column of each file
end

col_13_mean = mean(col_13_data ,2 ); % get the mean value for each row, over the files

[muhammad choudhry]

Its not quite right. its taking the mean of column_13 in each file and then giving me 79 mean values corresponding to 79 files.

I want the code to read row1 from each file so it will be 79 rows ....... take a means of them 79 values and store in a separate file and keep doing until the last value which is on 48th row... So my final file have 48 rows result.

similar to example below:

https://uk.mathworks.com/matlabcentral/answers/1742185-how-to-do-the-example-below-in-matlab-i-am-dealing-with-same-sort-of-problem-in-matlab?s_tid=srchtitle

[Karim]

ok i think i understand what you mean, i update the example code accordingly