Data in and out FAQs
See more about getting data into MLwiN
See more about getting data out of MLwiN
If you have any categorical variables for which there are no observations in some of the categories, see the FAQ How do I get rid of an unneeded dummy variable?
This error message will be produced if there are two variables with the same name in the Stata file you are trying to open. Note that MLwiN does not distinguish between small and capital letters, so for example variable1, Variable1 and VARIABLE1 will all be considered the same name. Inside Stata, change the names of any variables that MLwiN would consider to be the same, save your worksheet and try importing into MLwiN again.
Is it possible that MLwiN has problems reading underscores ("__")? For example, reading ___ABC the same as ABC ?
No, MLwiN should count '__ABC' and 'ABC' as different. To test whether MLwiN considers 2 names to be the same, open MLwiN without opening any worksheet (you can do this via the Programs menu, via a shortcut, or by selecting MLwiN in its folder in your Program files, or alternatively you can double click on an MLwiN worksheet to bring MLwiN up and then select New worksheet from the File menu to close the worksheet). From the Data manipulation menu select Names. In the window that appears, highlight any row and click the Edit name button. Type in one of the names you want to test. Highlight a different row, press the Edit name button again and type in the other name. If MLwiN considers these 2 names the same you will get an error message saying 'duplicate name(NAME)' (confusingly when you press OK it appears that the variable has been given the name you chose in spite of the error message, but if you press the refresh button in the top left corner of the Names window you will see that in fact the variable has reverted to its previous name). If MLwiN considers the names to be different you will get no error message. You can delete the variables (highlight the rows and press the Delete button at the top of the Names window) and test another pair of names, or you can leave the variables and name more variables one at a time to test whether a name is the same as any that you have already used.