code: public void computeVi(List seq, int pos, DoubleVector Vi, boolean isExp) {
  	Vi.assign(0.0);
  	
  	// start scan features for sequence "seq" at position "pos"
  	model.taggerFGen.startScanSFeaturesAt(seq, pos);
  	// examine all features at position "pos"
  	while (model.taggerFGen.hasNextSFeature()) {
  	    Feature f = model.taggerFGen.nextSFeature();
  	    
  	    if (f.ftype == Feature.STAT_FEATURE1) {
  		Vi.vect[f.y] += model.lambda[f.idx] * f.val;
  	    }
  	}
  	
  	// take exponential operator
  	if (isExp) {
  	    for (int i = 0; i < Vi.len; i++) {
  		Vi.vect[i] = Math.exp(Vi.vect[i]);
  	    }
  	}
      }
docs: Compute vi.
  
  @param seq the seq
  @param pos the pos
  @param Vi the vi
  @param isExp the is exp