How to import a column from an Excel file?

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Giuseppe on 16 Apr 2021
Answered: Giuseppe on 17 Apr 2021
This is my excel file:
Here I read the entire column A of the Excel sheet named "Lazy_eight" but the problem is that I have different sheets in which the column A has a different number of elements. So, I want to import only the numbers without specifing the length of the column vector.
I use the function readmatrix with the following syntax in order to read the entire column:
p_time = readmatrix('Input_signals.xlsx','Sheet','Lazy_eight','Range','A:A')
i get this in matlab workspace:
So, I wish to give to the "readmatrix" function only the first element of the column I want to import but I want that it stops at the last element, without specifing the coordinate of the last element in order to avoid the NaN that you can see in the last image. I want to import only the numbers without the NaN value.
I cannot read the initial and the last element (in this way: 'Range', 'A3: A13') beacuse in every sheet the column A (as the other ones) has a different number of elements.
Giuseppe on 16 Apr 2021
@João Mendes, thanks for your answer but I'd prefer to avoid to use other variables in my code.

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Accepted Answer

Clayton Gotberg
Clayton Gotberg on 16 Apr 2021
Since it seems that you just need to get rid of the NaN values, try using logical indexing with the isnan command.
p_time = p_time(~isnan(p_time));
This will remove all NaN values from the p_time vector.
As an example:
p_time = [5 NaN 3 7 NaN]; %double
eliminate_NaN_logical = ~isnan(p_time)
eliminate_NaN_logical = [1 0 1 1 0]; %logical
p_time_cropped = p_time(eliminate_NaN_logical)
p_time_cropped = [5 3 7]; %double
because MATLAB assumes you want a vector with only the elements for which eliminate_NaN_logical is true.

More Answers (1)

Giuseppe on 17 Apr 2021
Another more rapid solution is to use “rmmissing” function to remove “NaN” values from an array.

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