I have two csv files that have blog articles that I want to classify over a numerical feature. The two files have four features each: three numerical and one nominal (the blog article). I want to apply two filters to the files: NominalToString and StringToWordVector and then train the test set on the training set.
The problem I encounter is after applying the two filters on the two data sets separately, when i try to classify the test set on the training set i get the error that the two are not compatible. This means the vectors that represent the 'blog article' features after being applied the stringtovector filter are of different lengths for the two files.

I tried batch filtering from the cli with the command, but to the following command i get: 'input file formats differ'.
java weka.filters.unsupervised.
attribute.NominalToString -C 3 -b -i "C:\weka-files\TRAINING.csv" -o C:\weka-files\train.arff -r "C:\weka-files\POOL.csv" -s C:\weka-files\pool.arff

How to proceed?