How to import a column from an Excel file?

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.

[João Mendes]

Maybe you can just import the entire matrix and then, in matlab, isolate the first column? Or that is not what you want?

[Giuseppe]

@João Mendes, thanks for your answer but I'd prefer to avoid to use other variables in my code.

Answer 1

[Clayton Gotberg]

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)

returns

eliminate_NaN_logical = [1 0 1 1 0]; %logical

and

p_time_cropped = p_time(eliminate_NaN_logical)

returns

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.

Answer 2

[Giuseppe]

Another more rapid solution is to use “rmmissing” function to remove “NaN” values from an array.