I used the "lda" function in the MASS library of S-Plus (R) to do a linear discriminant analysis, and got the linear coefficients, say b1 and b2 for the 2 predictors x1 and x2. I have trouble to calculate the discrimiant scores for each observation, I used 3 ways to try to repeat the scores returned by the "predict" function in S-Plus:
1. b1*x1+b2*x2 2. b1*(x1-mean of x1)+b2*(x2-mean of x2) 3. b1* standardized x1+b2*standardized x2 (standardize: mean 0 & variance 1) none of the above procedures can repeat the scores returned by the "predict" function. However, method 2 & 3 can predict the classes correctly if using 0 as cutoff, juts like using the "predict function". What should be the correct formula to compute the scores for each observation? BTW, how to retrieve the linear coefficients from an lda object? I can't retrieve it by using @coef, @coefficients, etc. Thank you --------------------------------- [[alternate HTML version deleted]] ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help