How to change type of columb

UROOJRAFFAT

Can any one tell me how to change type of a columb from polynominal to date type because whenever i am changing in the excel sheet it gives me ? Mark   and i also formated the change with using nominal to date now for further regresion i have to change it as a date type.

BalazsBarany

Hi,

the best case is when you have actual dates or timestamps in your Excel file. You can check this by selecting the column and changing the date formatting. If it changes, then your cells are really set up as dates/timestamps, and RapidMiner can automatically read them as such. In this case, the formatting is irrelevant.

However, if you just change the type in Excel but use an already configured Read Excel operator, that will still try to import your data as nominal, which will fail or give you the ? (for unknown value). After changing the format in the Excel file, you should execute the import wizard again.

Otherwise, if your data are actually nominal (text, string), you'll need to use Nominal to Date with the appropriate format.
The pattern is the Java SimpleDateFormat one, documented here: https://docs.oracle.com/javase/8/docs/api/java/text/SimpleDateFormat.html

Regards,
Balázs