Splitting table field with multiple rows into separate columns

Hi,

I have a 459 x 1 table - each row of the table contains n rows of data by x 3 (see attached). Sort of like a nested field.

I would like to rearrange the table so the data appears in separate columns e.g. the first row in my table contains 726 x 3 data points and the second row contains 240 x 3 points. So I'd like to create three separate tables containing 726 x 1, 240 x 1 etc i.e. the first column of data, keeping the row numbers the same. Sorry its so simple but hard to explain!

Vertcat is no good as it just combines and concatenates all the data points in one matrix, which is not what I want. I'd like each row to contain the same data points but the column data to be in separate columns in the table or separate variables, whichever it easiest.

Any help will be most appreciated!

Answer 1

[Chris]

How about:

T = rows2vars(Data);
T(:,1) = [];

Or, if you really only want the first three:

T = table(Data{1,1},Data{2,1},Data{3,1});

This answer may be helpful too.

[Impala]

Hi Chris,

Thanks for responding.

Your code reorganises the data into row vectors. What I would like to do is split up the data into 3 columns. So currently, my table contains data in the first column that looks like this:

726x3 double

240x3 double

314x3 double

etc...

I want to split it into 3 columns like this:

row1 col1: 726 x 1 (the first coordinate point)

row1 col2: 726 x 1 (the second coordinate point)

row1 col3: 726 x 1 (the third coordinate point) etc.

Is there a way to do this?

Thanks!

Answer 2

[Chris]

Whoops. It looks like each array in Data is a cell, so you'll need to drill down a bit. To repack the first cell:

load('Data.mat');
newtable = array2table(Data{1,1}{1});

Breaking it down:

T1 = Data{1,1}; % Get the cell inside this row
T2 = T1{1}; % Access the double array inside the cell
newtable = array2table(T2); % Make a new table

For the first three cells, each has a different number of rows, which doesn't seem to be what tables are meant for. If you want them side by side in a parent table, you'll have to pack them back into cells as far as I can tell.

newtable = table([{array2table(Data{1,:}{1})}, {array2table(Data{2,:}{1})}, {array2table(Data{3,:}{1})}])

newtable = table
                         Var1                      
    _______________________________________________

    {726×3 table}    {240×3 table}    {314×3 table}

newtable{:,1}{1}

ans = 726×3 table
      Var1        Var2        Var3  
    ________    ________    ________

    0.019608    0.036774    0.053406
    0.019302    0.036621    0.053558
    0.019455    0.036392    0.053558
    0.019379    0.036621     0.05394
    0.019684    0.036011    0.053787
    0.019531    0.036392    0.054092
    0.019455    0.036316    0.053711
     0.01915    0.036545    0.053864
    0.019455     0.03624    0.053864
    0.019455    0.036316    0.053558
    0.019379    0.036469    0.053406
    0.019608    0.036316    0.053635
     0.01915    0.036163    0.053864
    0.019684    0.036545     0.05455
    0.019836    0.036316    0.054321
     0.01915    0.035782    0.053635

Does that help?

fyi, for this kind of arrangement, I prefer working with struct arrays.

[Impala]

Hi Chris,

Thanks once again for the help.

That is helpful but what I'm looking to do is split up the contents of each cell into 3 columns. The data I've provided is accelerometer data and I would like each component (x, y, z) in a separate column within the same variable - please see attached pic.

Interestingly, the original data was in a structarray but I thought it might be easier to work in a table. I've attached the struct array data too. Sorry for not being clear about what I'm looking to do!

Thanks!