NULLPointerException during text processing

Hi, 
I am trying to perform some simple text analysis using KNIME. My process begins by using a normal 'XLS reader' or a 'text reader', followed by 'row filter' which executes fine. This step is followed by 'Strings to document' to convert every string into a document. Following this step, no steps execute. I have tried using 'POS Tagger', 'BoW Creator', 'Row Filter', 'Number Filter' etc, but each one of these gives me a 'NULLPointerException'. Why is this the case? 
My input document is a text file with about 300,000 rows coming from the database. I have checked that none of the rows in the file is NULL. 
How can I get rid of this error? 
This is URGENT, any help would be highly appreciated. 

Cheers 
P

Hi,

which KNIME version are you using? Could you please send me the stack trace. You can do this by setting the log level for the KNIME GUI to debug (File->Preferences->KNIME->KNIME GUI) and copy paste the stack trace from the console, or copy paste it from the log file (..path to your workspace/.metadata/.log). Thank you.

Cheers, Kilian

Hi,

btw. since KNIME Textprocessing v. 2.9 you can apply preprocessing nodes, such as Stopword filter etc. directly on the list of documents, which is a lot faster than preprocessing a bag of words. E.g.:

... ->Strings to Document->Stopword filter->Number filter->...->BoW

Use the BoW node after the preprocessing nodes to create a bag of words.

See also:

http://tech.knime.org/blog/textprocessing-version-v29-released

http://tech.knime.org/blog/knime-ugm-2014-text-mining-workshop

Cheers, Kilian

Hi,

this might be the same problem as posted here:

http://tech.knime.org/forum/knime-textprocessing/bow-error-when-processing-large-data#comment-31524

It is a bug. However there is a workaround to avoid the error. Please see the post for the workaround.

Cheers, Kilian