Patch for ngram.cc

[Andreas Stolcke]

Dear All,

a rather embarassing bug in ngram causes it to mess up the mixture 
weight for the second mixture model (-mix-lm) when three or more
models are interpolated.  This problem exists in all versions of SRILM
prior to 1.2 (which won't be released for a while), so please apply the
patch below if this bug affects you.

--Andreas

*** /tmp/T0EFaaMN	Thu Oct  4 12:32:01 2001
--- ngram.cc	Wed Oct  3 19:51:14 2001
***************
*** 463,470 ****
  					    mixLambda2/totalLambda);
  	}
  
  	mixLM = makeMixLM(mixFile, *vocab, classVocab, order, mixLM,
! 				    1.0 - totalLambda - mixLambda);
  
  	useLM = new BayesMix(*vocab, *useLM, *mixLM, bayesLength,
  						    mixLambda, bayesScale);
--- 463,472 ----
  					    mixLambda2/totalLambda);
  	}
  
+ 	double mixLambda1 = 1.0 - totalLambda - mixLambda;
+ 
  	mixLM = makeMixLM(mixFile, *vocab, classVocab, order, mixLM,
! 				    mixLambda1/(mixLambda1 + totalLambda));
  
  	useLM = new BayesMix(*vocab, *useLM, *mixLM, bayesLength,
  						    mixLambda, bayesScale);