[Crf-users] Urgent problem about the input data structure

[Anan L. <ana...@gm...>]

Hi,all
I am a beginner  to use CRF and Semi-CRF. I am attracted by the fancy
semi-crf model. I download the CRF package from http://crf.sourceforge.net/
currently I can run the demo of "segment.java". I have the following
questions:
Question1:
For the train/test data format, my understanding is below:
for the train/test data, X denotes the observation and Y denotes the label.
In "us50.train.tagged", each word corresponds to Xi which is one node of
sequence X={X1,X2,...,Xn} and the number behind "|" is the label.
Therefore, for the input X, each Xi is only one dimension.
But in my problem, each Xi is a vector. let us assume Xi is m dimention, and
X has n Xi, my input is a matrix with m*n size.Now I am confused how to
input my train/tet data into semi-crf model.
Question 2:
 When I run the segment.java, I change the model type to 'semi-markov', but
it stop when iteration gets 18. the model works quite worse than the one
with crf model.
Can someone show me how to get a well-performed semi-crf?
Thanks a lot!
leo