How to deal with nested arrays where the columns and rows are in different dimensions?

Hello everyone,

In some previous questions I have asked about defining a specific data structure which gave me splendid answers and a better understanding of organizing those data. Now, for a deeper meaning I would like to know the following:

I have a (72x1 cell) which content is defined by the following block/section:

COLUMN1

ROW1 Text Nr.1

ROW2 2345x3 double

ROW3 Text Nr.2

....times 24 to get the mentioned 72x1 cell array

My goal now is to unnest the 2345x3 double contents in a way, that I obtain the following data order:

COLUMN1 COLUMN2 COLUMN3

Text Nr.1 (empty) (empty)

value 1 value 1 value 1

value 2 value 2 value 2

value 3 value 3 value 3

value 4 value 4 value 4

value 5 value 5 value 5

value 6 value 6 value 6

value 7 value 7 value 7

etc. etc. etc.

Text Nr.2 (empty) (empty)

Text Nr.1 (empty) (empty)

value 1 value 1 value 1

value 2 value 2 value 2

value 3 value 3 value 3

value 4 value 4 value 4

value 5 value 5 value 5

value 6 value 6 value 6

value 7 value 7 value 7

etc. etc. etc.

Text Nr.2 (empty) (empty)

However this requires me to know about the new shifted positons without overwriting any data:

I tried to write a code with a (for loop?) but I am even unsure how to start nor to implement my thought process in a proper solution.

Hence I would like to know a method which allows me to unnest the above mentioned example into a cell array (N x 1) where N of course is the expanded version of the old nested cell array.

Stay safe and healthy,

David

Additional Notes:

For anyone asking about my intenton behind this question: I succesfully printed some parts in 3D printer yesterday using some of your answers by exporting those into different gcode converters which require different data structures depending on the current used software. In my upcoming research I would like to establish a readable communication path between some gcode readers and 3d printers. Therefore I have already adjusted my code for exporting finished data files as well as textboxes for inputing new data. The only struggle that I am currently dealing is the fact, that I am not familiar with the matlab cell editing operations which lead me to your much more refined approach regarding this matter.

Answer 1

[Jan]

I do not undestand why "Text Nr.1" appears multiple times. If this is a typo only:

In  = {your cell};
Out = cell(size(In));
for k = 1:numel(In)
    if ischar(In{k});
        Out{k} = {In{k}, [], []};  % Or '' instead of [] ?
    else
        Out{k} = num2cell(In{k});
    end
end
Result = cat(1, Out{:});

If you provide a tiny set of input data, I could test my code.

[David Mrozek]

Here is a an example.

[David Mrozek]

It was not a typo. I need to repeat the text.

[Jan]

Okay. Then I do not understand, where "Text Nr. 1" and "Text Nr. 2" should appear. I guess that "value 7 value 7 value 7" doesnot mean 7 equal values also.

Seeing the example data, I get the impression, that you do not have to repeat the strings, but that the strings have the same contents. Then I assume, that my suggested code does, what you want. Please explain, if the problem is solved or if the result differes from your needs.

[David Mrozek]

Yes I will try explain the problem again. My major issue is that the 2345x3 double contains nested data with a text above and below the 2345x3 double:

COLUMN1

Text 1

value* *nested 2345x3 double

Text 2

and so on...

This above mentioned block repeats a total of 24 times in a column. However I need the doubles, which only appear in one column, to be unnested so that my inital block expands to 3 columns:

COLUMN1 COLUMN2 COLUMN3

Text 1 (empty entry) (empty entry)

(value1 value2 value3 )** **unnested 2345x3 double

(the entries continue here until all rows are displayed)**

Text 2 (empty entry) (empty entry)

[the next block/section will be appended under the above block/section...]

This results in a new amount of row:

24 times 2435 (original row amount of the unnested double) +

2 times 24 = 48 text messages (above and under each unnested double entry) =

58488 rows in total after unnesting the double entries and appending them with the text messages together

I hope I could give a little bit more details on my problem.

[Jan]

I do not understand, why you do not mention, how the result of my posted code differs from your expectations.

You have posted some example data in the DATA.mat file. There I find a cell with this contents:

72×1 cell array
    {'StartCurve' }
    {1268×3 double}
    {'EndCurve'   }
    {'StartCurve' }
    {1268×3 double}
    {'EndCurve'   }
    {'StartCurve' }
    {1268×3 double}
    {'EndCurve'   }
    {'StartCurve' }
    {1268×3 double}
    {'EndCurve'   }
    ...

The double values are 1268×3 double matrices and I guess, that you mean this by "*nested 2345x3 double". I do not see anything "nested" here.

The code contains 48 char vectors 'StartCurve' and 'EndCurve'. I guess this is what you call "Text 1" and "Text 2".

The other 24 cell elements are 1268 x 3 vectors.

My code joins these data to a 30'480 x 3 cell matrix: 48 text rows and 24 * 1268 numerical rows.

Result = {'StartCurve', [],      []; ...
          -75,          -4.8308, 5; ...
          ...  1267 further rows
          'EndCurve',   [],      []; ...
          'StartCurve', [],      []; ...
          -38,          -4.8308, 5; ...
          ...  1267 further rows
          'EndCurve', [], []; ...
          ... and so on
          }

As far as I can see, I've posted a working code yesterday. Please take the time to try it and to explain, what changes you need.

[David Mrozek]

I have checked the data and the code now and it works. Thanks!