Create new column in table based on another column value

I have a table with the list of User IDs and I used "Groupummary" to determine the number of occurences of each ID. My table T:

ID Occurrences

123 9

345 1

234 3

I need to create another column in the table to mark the ID as "unique" or not based on the number of occurrences.

Expected output:

ID Occurrences Unique

123 9 No

345 1 Yes

234 3 No

I'm using the following code, but I get error saying the number of rows should match the length of table:

if T.Occurences> 1

T.Unique = "No";

else

T.Unique = "Yes";

end

How do I check the length of table and fill the "Unique" column for each corresponding cell?

Answer 1

[Steven Lord]

Let's start with a sample table.

T = table([123; 345; 234], [9; 1; 3], 'VariableNames', ["ID", "Occurrences"])

T = 3x2 table
    ID     Occurrences
    ___    ___________

    123         9     
    345         1     
    234         3     

Fill in the Unique variable with a default value.

T.Unique = repmat("No", height(T), 1)

T = 3x3 table
    ID     Occurrences    Unique
    ___    ___________    ______

    123         9          "No" 
    345         1          "No" 
    234         3          "No" 

Change the value of the Unique variable based on the contents of the Occurrences variable.

T.Unique(T.Occurrences == 1) = "Yes"

T = 3x3 table
    ID     Occurrences    Unique
    ___    ___________    ______

    123         9         "No"  
    345         1         "Yes" 
    234         3         "No"  

[Namrata Goswami]

Thank you!