# How to assign to an empty array

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karishma koshy on 2 Aug 2019
Commented: karishma koshy on 2 Aug 2019
Hi How to check in a column of table whether every row is assigned or not. If not how can I add a new value. I have assigned till 4. Now I want to assign 5 to the empty unassigned space.
i have two tables.
1 22 1
1 24 2
1 25 3
1 32 4
2 22.5 1
2 24.7 2
2 25.5 3
2 32.6 4
2 34
i want to assign ID for 34 as 5... if theres any other empty cell in table 2 then 6, 7 and so on. how can i use it inside a for loop so if theres any empty field, it inserts number after the last value assigned
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karishma koshy on 2 Aug 2019
i have two tables.
1 22 1
1 24 2
1 25 3
1 32 4
2 22.5 1
2 24.7 2
2 25.5 3
2 32.6 4
2 34
i want to assign ID for 34 as 5... if theres any other empty cell in table 2 then 6 , 7 and so on

madhan ravi on 2 Aug 2019
Edited: madhan ravi on 2 Aug 2019
It's always better that you provide the data as Rik mentioned:
column = 1;
idx = cellfun('isempty',table2cell(T(:,column))); % T your table
T{idx,column} = {5}
edit:
So you have two tables say T1 and T2:
column = 3;
T = [T1;T2]; % concatenate them as one
idx = cellfun('isempty',table2cell(T(:,column))); % find the empty ones
STartwith = 5;
T{idx,column} =num2cell((1:nnz(idx)).' - 1 + STartwith)
karishma koshy on 2 Aug 2019
% make arrays into tables
% assign id's to data2
data2.id = (1:size(data2,1))';
% find row numbers in frame1 data that have matching rows in frame2 data
% (these are the rows of result1 that have a 1 in them)
iRow = find(any(result1,2));
% find row numbers in frame 2 where each match occurs
[id,~] = find(result1');
% assign these ids in data1
% rows that don't have a matching ID will be assigned NaN
data1.id = NaN(size(data1,1),1);
data1.id(iRow) = id;
% display results
disp(data1)
disp(data2)
i want a for loop of the same. inside the for loop i want to assign the ID to data1. Then i want to find the assigned point in frame i. if no assigned point, i want to assign as next available ID. If assigned point, I want to set ID for i+1 equal to ID for i. result1 is a logical array
Expected Output
frame centrex centrey ID
1 2 3 1
1 7 9 2
2 3 3 1
2 8 10 2
3 5 20 3
3 8 9 2
so on