Concatenation is missing values

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Charles D'Onofrio
Charles D'Onofrio 2018-12-6
评论： Stephen23 2025-9-26，10:38
I am using the command:
doubArray = cat(1,cellStruct{:,3});
to extract an array of numeric values from a cell structure of mixed variable types. All of the variables in column 3 of the cell structure are of data type “double“.
The resulting array is missing 33 of the 116397 expected entires. The missing 33 entries are from a variety of locations within the cell structure and there does not appear to be any rhyme or reason behind which entries are missing.
Has anyone encountered this problem before and know of a solution?
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Jan
Jan 2018-12-6
"The resulting array is missing 33 of the 116397 expected entires."
The cat command does not ignore values. Therefore I assume that the expectation of 116397 elements is the actual problem. Why do you assume this amount of data? How do you determine, which elements are missing? What does this reply:
S = sum(cellfun('prodofsize', cellStruct(:,3)))
This is the number of elements of all arrays contained in the 3rd column of cellStruct - by the way: isn't the part "Struct" in the name confusing here?
Charles D'Onofrio
Charles D'Onofrio 2018-12-6
I have attached a representative cell structure and double array.

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Stephen23
Stephen23 2018-12-6
编辑：Stephen23 2018-12-6
33 of the cells in the third column contain empty arrays:
>> find(cellfun('isempty',cellStruct(:,3)))
ans =
21968
21969
27848
35808
43424
52648
52649
52650
52651
52652
52653
52654
52655
60284
60285
60286
60287
60288
60289
60290
60291
60292
60293
60294
60295
60296
60297
60298
60299
65762
65763
65839
65840
While the rest of the cells in the third column apparently have one row:
>> find(cellfun('size',cellStruct(:,3),1)>1)
ans = []
In any case, the total number of rows in all of the cells in the third colum is:
>> sum(cellfun('size',cellStruct(:,3),1))
ans = 116364
And that is the exact number of rows that your numeric array contains:
>> size(doubArray,1)
ans = 116364
So far nothing suggests that any data has gone "missing" when concatenating those cell contents.
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Tjeerd
Tjeerd 2025-9-26，9:01
I have a similar problem in that NaNs are excluded in the concatenated array. Is there a way to include them, such that the answer in your example would be:
1 2 3
nan nan nan
4 5 6
Stephen23
Stephen23 2025-9-26，10:38
Ran in:
"I have a similar problem in that NaNs are excluded in the concatenated array."
None of the concatenation operators "exclude" NaN values. Lets try them all right now:
[1:3;nan(1,3);4:6]
ans = 3×3
1 2 3 NaN NaN NaN 4 5 6
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<mw-icon class=""></mw-icon>
vertcat(1:3,nan(1,3),4:6)
ans = 3×3
1 2 3 NaN NaN NaN 4 5 6
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
horzcat(1:3,nan(1,3),4:6)
ans = 1×9
1 2 3 NaN NaN NaN 4 5 6
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
I do not see any values being "excluded".
"Is there a way to include them.."
Yes, you include the NaNs in the arrays being concatenated.

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