how do I create this loop?

I have a timetable that I'm converting to an array. Some of the columns are NaNs so initially, I just changed the columns to zeros before converting it but I don't want to do this since not all values in the column are necessarily NaNs and I don't want to lose that possible data. I was thinking of creating a loop so that if the values are NaNs, it'll be changed to a zero and if the value is something else, it'll be left alone. This is what I tried writing for a column called G

 for c = 1:length(TT(:,'G'))
    if TT(c,'G')= nan
        TT(c,'G') = 0;
    else
        TT(c,'G') = TT(c,'G');
end

I know i'm calling the if function wrong but i'm not sure how to fix it. if statements always trip me up for some reason

Answer 1

[Star Strider]

It might be easier to use the timetable2table (link) function, then the table2array (link) function.

I have no idea if this would work with your data. You will have to experiment.

[Susan Santiago]

Thanks for the advice but that doesn't work in this case. All of the values need to be the same variable type

[Star Strider]

My pleasure.

We would have to see at least a representative sample of your timetable, ideally as a ‘mat’ file, so all the variable types and other relevant information is available.

[Susan Santiago]

This is the time table. As you can see, there are 4 columns that are all NaNs but that won't necessarily always be the case

[Star Strider]

It was something of a challenge for me to figure out how to convert your 'NAN' string entries to numeric NaN values. I am still not certain what you want to do.

This will at least get you started (assuming you already have your ‘TT’ table in your workspace):

TT_T = timetable2table(TT);                                 % Convert To Table
TT_C = table2cell(TT_T);                                    % Convert To Cell
TT_L = cellfun(@(x)strcmpi(x, 'NAN'), TT_C);                % Find 'NAN' Strings
TT_C(TT_L) = {NaN};                                         % Convert String 'NAN' To Numeric {NaN}
TT_M = cell2mat(TT_C(:, 3:end));                            % Data Without ‘datetime’ Objects

The final version of ‘TT_C’ is a cell array with the string 'NAN' elements replaced with numeric NaN elements. The ‘TT_M’ matrix is an array of the data without the first two columns. If you want to include them, use the datenum function to convert them to numeric values. I would not recommend that, although it could be necessary, depending on how you choose to process your data.

[Susan Santiago]

This is perfect, thanks so much!

[Star Strider]

As always, my pleasure!

Answer 2

[Andrei Bobrov]

zrs = zeros(size(TT,1),1);
TT.G = zrs;
TT.SG = zrs;

[Susan Santiago]

Can you explain this a little bit. Would this replace the code I posted or be part of it. I tried running this in my code and it said "Undefined function 'isnan' for input arguments of type 'timetable'.

Error in flux_loop2 (line 28) out(isnan(out)) = 0;"

[Andrei Bobrov]

I am fixed my answer.

[Susan Santiago]

This would just change the whole column to zeros wouldn't it? I explained that that's not what I want to do