#二次判别
library(mvstats)
(qb=qda(G ~ X1 + X2 + X3 + X4))
Call:
qda(G ~ X1 + X2 + X3 + X4)

Prior probabilities of groups:
  1   2
0.5 0.5

Group means:
        X1       X2        X3        X4
1 51.24344 2.579737  4.065525 9.3479625
2 73.63494 1.767450 -4.887562 0.3462875