Mean of Multiple Data

Hey, I am a newbie in MATLAB, wanna ask a question: I have a data of frequency (column 1) and the impedance (column 2), and I did multiple measurements, let's say 5 measurements.

I want to plot the graph of the average value of the impedance in each frequency. I tried to find the mean of it, but it turns out that the coding I did find the average of the whole impedance (so i only got 1 average value, it's suppose to be 1 average value for each frequency).

Can somebody help me with the code? I use the .txt files as the data source, by the way.

Thank you for the help.

Answer 1

[Evgeny Pr]

frequency = [1, 2, 3, 4, 5, 6]
impedance = [6  2  7  5  6  7
            10  9  5  1  7  9
             7  8  4  7  4  3
             6  2  4  6  7  2
             2  2 10  4 10 11]
meanImpedance = mean(impedance, 1) % Rows - measurements

plot(frequency, meanImpedance)

[Tesa]

thaks but i have seperated files of impedance. so in first file i have the frequency information and first measurement of impedance. in 2nd file, in 3rd one and so on. I can not use the code you've given. please help

[Evgeny Pr]

Well it is not that difficult to do :)

For example:

% load_measurement_data - your function for load data from txt file
freqAndImpedance1 = load_measurement_data('measurements1.txt')
freqAndImpedance2 = load_measurement_data('measurements2.txt')
freqAndImpedance3 = load_measurement_data('measurements3.txt')

% only frequences for all measurements
frequency = freqAndImpedance1(:,1);

% all measurements for impedance (Columns - measurements)
impedances = [freqAndImpedance1(:,2), ...
              freqAndImpedance2(:,2), ...
              freqAndImpedance3(:,2)];

meanImpedance = mean(impedances, 2);
plot(frequency, meanImpedance)

[Tesa]

thanks! :D you help a lot :)

[Tesa]

I've got the feedback like this: Undefined function 'load_measurement_data' for input arguments of type 'char'. Is there something wrong? Thanks :)

[Tesa]

and also, what does this one mean? meanImpedance = mean(impedances, 2); Thanks!