How do I extract data from a structure and put them all in one single array?

I have a 1X31 struct with two fields, I would like to extract all the data from the second one, and put them all in one single array.

How can I do that?

Here are some images to illustrate how they are arranged.

So what I want to do is to create an array that contains dataTT(1).Data + dataTT(2).Data + ... dataTT(n).Data

Answer 1

[Stephen23]

https://www.mathworks.com/matlabcentral/answers/1656435-tutorial-comma-separated-lists-and-how-to-use-them

S = vertcat(dataTT.Data)

[Stephen23]

I guess your next request will be to convert that string data into numeric... Here are some approaches:

S = ["{1.23,4.56,7.89}";"{9.87,6.54,3.21}";"{12.3,45.6,78.9}";"{98.7,65.4,32.1}"]

S = 4×1 string array
    "{1.23,4.56,7.89}"
    "{9.87,6.54,3.21}"
    "{12.3,45.6,78.9}"
    "{98.7,65.4,32.1}"

M = sscanf([S{:}],'{%f,%f,%f}',[3,Inf]).'

M = 4×3

1.2300 4.5600 7.8900 9.8700 6.5400 3.2100 12.3000 45.6000 78.9000 98.7000 65.4000 32.1000

M = double(split(replace(S,["{","}"],''),','))

M = 4×3

1.2300 4.5600 7.8900 9.8700 6.5400 3.2100 12.3000 45.6000 78.9000 98.7000 65.4000 32.1000

[Luis Ricardo Rivera Goitia]

Excelent! It worked Thx

Answer 2

[Image Analyst]

You forgot to attach your data in a .mat file with the paperclip icon so we can't try it with your data. You can try these things:

v = {dataTT.Topic}

or

v = vertcat(dataTT.Topic)

Same for the Data field

[Luis Ricardo Rivera Goitia]

Thx a lot it worked using v = vertcat(data.Topic) or vertcat(dataTT.Data).

[Image Analyst]

You're welcome. Just additional info to extend this into future situations you might encounter: If the numbers were single numbers, not cell arrays of 3 numbers then you could do

v = [structName.fieldName] % Concatenate all fields into a single vector.

For a real world example, where mask is a binary image with several "blobs" that you want to measure the area of:

props = regionprops(mask, 'Area'); % Returns a structure with "Area" as a field of the structure.
allAreas = [props.Area]; % Concatenate all areas into a single double vector.

I use it that way all the time.

If my replies helped you, perhaps you could click the "Vote" icon. 🙂