NaN when I type "known" variables (like pi, etc) in an editable uitable

Hi,

I have an uitable with 2 columns and its ColumnFormat are char and numeric; the numeric column is editable.

When I type pi or pi/2 it returns 'NaN' where I type.

Matlab Help suggests to use CellEditCallback command, but I don't understand how I shoud use it and how can it solves my problem.

Thanks

Answer 1

[Jan]

"Numeric" means numeric, such as 1.23 or -1e-16, while pi/2 has to be interpreted. The CellEditcallback (you can use this term to let Google find more details for you) can call eval() to evaulate this expression. But then a small test would be fine to control that no mad user tries to input '!format C:', because even this command would be evaulated (of course not successfully, but I do not post dangerous commands here). A minimal test is to exclude all strings, which contain '!', 'dos' and 'system', but even the local variables of the CellEditCallback function can be overwritten, 'error' let the program stop, 'quit' closes Matlab etc.

Perhaps converting the string to a sym expression at first is more secure.

[Marco]

I thought CellEditCallback was a function can I use when I finished to type. For example to convert pi/2-string into its numeric value.

Answer 2

[Azzi Abdelmalek]

If you want to type pi/2, then make your column format char

[Marco]

Done, but it returns NaN

[Azzi Abdelmalek]

Because the previous value was not a string

[Azzi Abdelmalek]

If you want to use pi/2 as numeric , just use the function str2num

[Marco]

where should I use it ?