"Lower accuracy of libsvm in rapidminer vs weka with same parameters"

njasaj

Hi,
I am really getting confused. I used a same data set with same parameters in weka and rapidminer for classification with libsvm. the strange result was that weka accuracy for prediction was 15 percent higher than rapidminer???(I used same C and same kernel and same gamma for rbf kernal).I think there is something wrong with weka. it's accuracy on training set for testing phase is 100%.
Can any body explain it?
Thanks a lot.

njasaj

In addition to above i must say that my data set is imbalanced. rapidminer fail to predict the two smaller classes and just predict the largest class
725  188    211
3      1          1
1      0            1

but weka with same parameters gives
729    0    0
124    65    0
111    0    101
I did not use any weight for classes in weka.Help me please and tell me what is wrong with rapidminer?

thank you.