Can't Input Tab Delimited file to Stanford Classifier - nlp

Question

I'm having a problem inputting tab delimited files into the stanford classifier.
Although I was able to successfully walk through all the included stanford tutorials, including the newsgroup tutorial, when I try to input my own training and test data it doesn't load properly.
At first I thought the problem was that I was saving the data into a tab delimited file using an Excel spreadsheet and it was some kind of encoding issue.
But then I got exactly the same results when I did the following. First I literally typed the demo data below into gedit, making sure to use a tab between the politics/sports class and the ensuing text:
politics Obama today announced a new immigration policy.
sports The NBA all-star game was last weekend.
politics Both parties are eyeing the next midterm elections.
politics Congress votes tomorrow on electoral reforms.
sports The Lakers lost again last night, 102-100.
politics The Supreme Court will rule on gay marriage this spring.
sports The Red Sox report to spring training in two weeks.
sports Messi set a world record for goals in a calendar year in 2012.
politics The Senate will vote on a new budget proposal next week.
politics The President declared on Friday that he will veto any budget that doesn't include revenue increases.
I saved that as myproject/demo-train.txt and a similar file as myproject/demo-test.txt.
I then ran the following:
java -mx1800m -cp stanford-classifier.jar edu.stanford.nlp.classify.ColumnDataClassifier
-trainFile myproject/demo-train.txt -testFile myproject/demo-test.txt
The good news: this actually ran without throwing any errors.
The bad news: since it doesn't extract any features, it can't actually estimate a real model and the probability defaults to 1/n for each item, where n is the number of classes.
So then I ran the same command but with two basic options specified:
java -mx1800m -cp stanford-classifier.jar edu.stanford.nlp.classify.ColumnDataClassifier
-trainFile myproject/demo-train.txt -testFile myproject/demo-test.txt -2.useSplitWords =2.splitWordsRegexp "\s+"
That yielded:
Exception in thread "main" java.lang.RuntimeException: Training dataset could not be processed
at edu.stanford.nlp.classify.ColumnDataClassifier.readDataset(ColumnDataClassifier.java:402)
at edu.stanford.nlp.classify.ColumnDataClassifier.readTrainingExamples (ColumnDataClassifier.java:317)
at edu.stanford.nlp.classify.ColumnDataClassifier.trainClassifier(ColumnDataClassifier.java:1652)
at edu.stanford.nlp.classify.ColumnDataClassifier.main(ColumnDataClassifier.java:1628)
Caused by: java.lang.ArrayIndexOutOfBoundsException: 2
at edu.stanford.nlp.classify.ColumnDataClassifier.makeDatum(ColumnDataClassifier.java:670)
at edu.stanford.nlp.classify.ColumnDataClassifier.makeDatumFromLine(ColumnDataClassifier.java:267)
at edu.stanford.nlp.classify.ColumnDataClassifier.makeDatum(ColumnDataClassifier.java:396)
... 3 more
These are exactly the same results I get when I used the real data I saved from Excel.
Even more though, I don't know how to make sense of the ArrayIndexOutOfBoundsException. When I used readline in python to print out the raw strings for both the demo files I created and the tutorial files that worked, nothing about the formatting seemed different. So I don't know why this exception would be raised with one set of files but not the other.
Finally, one other quirk. At one point I thought maybe line breaks were the problem. So I deleted all line breaks from the demo files while preserving tab breaks and ran the same command:
java -mx1800m -cp stanford-classifier.jar edu.stanford.nlp.classify.ColumnDataClassifier
-trainFile myproject/demo-train.txt -testFile myproject/demo-test.txt -2.useSplitWords =2.splitWordsRegexp "\s+"
Surprisingly, this time no java exceptions are thrown. But again, it's worthless: it treats the entire file as one observation, and can't properly fit a model as a result.
I've spent 8 hours on this now and have exhausted everything I can think of. I'm new to Java but I don't think that should be an issue here -- according to Stanford's API documentation for ColumnDataClassifier, all that's required is a tab delimited file.
Any help would be MUCH appreciated.
One last note: I've run these same commands with the same files on both Windows and Ubuntu, and the results are the same in each.

Answer 1

Use a properties file. In the example Stanford classifier example
trainFile=20news-bydate-devtrain-stanford-classifier.txt
testFile=20news-bydate-devtest-stanford-classifier.txt
2.useSplitWords=true
2.splitWordsTokenizerRegexp=[\\p{L}][\\p{L}0-9]*|(?:\\$ ?)?[0-9]+(?:\\.[0-9]{2})?%?|\\s+|[\\x80-\\uFFFD]|.
2.splitWordsIgnoreRegexp=\\s+
The number 2 at the start of lines 3, 4 and 5 signifies the column in your tsv file. So in your case you would use
trainFile=20news-bydate-devtrain-stanford-classifier.txt
testFile=20news-bydate-devtest-stanford-classifier.txt
1.useSplitWords=true
1.splitWordsTokenizerRegexp=[\\p{L}][\\p{L}0-9]*|(?:\\$ ?)?[0-9]+(?:\\.[0-9]{2})?%?|\\s+|[\\x80-\\uFFFD]|.
1.splitWordsIgnoreRegexp=\\s+
or if you want to run with command line arguments
java -mx1800m -cp stanford-classifier.jar edu.stanford.nlp.classify.ColumnDataClassifier -trainFile myproject/demo-train.txt -testFile myproject/demo-test.txt -1.useSplitWords =1.splitWordsRegexp "\s+"

Answer 2

I've faced the same error as you.
Pay attention on tabs in the text you are classifying.
Caused by: java.lang.ArrayIndexOutOfBoundsException: 2
This means, that at some point classifier expects array of 3 elements, after it splits the string with tabs.
I've run a method, that counts amount of tabs in each line, and if at some line you have not two of them - here is an error.