Dear Sir or Madam， I am a researcher in natural language processing and the main purpose of this e-mail is to inquire some questions about the source codes in the project “Hidden Markov Model Tagger Annotator” which is written in java. The function I am puzzled in the class ModelGeneration is described as follow: private double [] calculate_lambda(int N); As the source code pointed out, the value of f2 is calculated in the different form: f2=(f(t1,t2)-1)/(f(t1)-1); while as far as I am concerned, the formula should be computed in accordance with the following formula(Brants, 2000): f2=(f(t2,t3)-1)/(f(t2)-1). This phenomenon is also happen when calculating the value of f1. So I’ve wonder if your approach is also ok to estimate the value of lambda1, lambda2 and lambda3 or if there is a bug in this process. Thank you so much for your valuable time and I am really looking forward to your early reply. Yours Sincerely, Yanzhou Huang
