As is explained in the documentation for 'readtable' , the 'TreatAsEmpty' option only applies to numeric columns. Since the second column of the sheet contains only string data, the string 'none' is not replaced.As a workaround, the string can be manually replaced with a string 'NaN' using logical indexing :
>> x.Col2(strcmp(x.Col2, 'none')) = {'NaN'}
x =
Col1 Col2 Col3
____ _____ ____
5 'abc' 1
NaN 'xyz' 2
1 'NaN' 3
Note that since this column of the table contains strings (in cells), the entry must be replaced by a cell entry and not an explicit string or numeric value.
In addition to the above, one can also use the "standardizeMissing" function to replace instances of 'none' (across all of the table's variables) with an empty string. The link for the "standardizeMissing" is given below:
Alternately, Col2 may usefully be converted to a categorical variable. The 'none' elements can then be turned into undefined elements simply by deleting the 'none' category.
Another way to replace the 'none' elements is to use the standardizeMissing function, which can be used to replace instances of 'none' (across all of the table's variables) with an empty string. This is a more standard way to indicate a missing string value.
