Importing excel data to Matlab.

I am importing a data set from an Excel file into MATLAB to plot it and ID max, min and period. The code is working fine but MATLAB is reading the data as the row number, and not as the values inside each cell. For example, instead of my period being 12 sec (as it should be) it is 60, because one peak is in row 61 and the next in row 121. I hope that makes sense.

[jonas]

Can you attach the file and briefly explain what your desired output is?

[Ricardo Whitaker]

%My code is right below.

X = xlsread('Loop Calculation','A2:A302');
Y = xlsread('Loop Calculation','B2:B302');
TF1 = islocalmin(Y,'MinProminence',0.1);
MinTime = find(TF1);
Period = mean(diff(MinTime));
plot(X,Y,X(TF1),Y(TF1),'or');
xlabel('Time (s)');
ylabel('Pressure (inH2O)');
title('Time vs. Pressure');

[Ricardo Whitaker]

Dear Jonas, As you can see in the EXCEL file, I have values for a certain pressure and time and my output is giving me the correct answer, however as the row position of the cell, and not its values. You know?

Answer 1

[Walter Roberson]

Your X values appear to be in fractions of days. To convert to seconds:

X = xlsread('Loop Calculation','A2:A302') * (24 * 60 * 60)

[Ricardo Whitaker]

If you look at the Workspace, my MaxTime shows the respective row in which the peak occur, but not exactly the time value. On top of that, I would like to have the respective pressure at that time, meaning the peak value. Could you help me with that? I appreciate your answer.

[Walter Roberson]

X(MaxTime)

Y(MaxTime)

[Ricardo Whitaker]

Works great. Thank you so much for the help.