why my SVM don't have a support vector?

Hi,all. I use SVM (matlab) to classify a dataset, but I come across some problem. when the training over, we will get a structure whose name is svmStruct, and it contains several fields. However, when I get my svmStruct, I find there is no support vectors and alpha, the result is as follows:

My code for training svm is:"svmStruct = svmtrain(Asvm_r', b_r,'Kernel_Function','polynomial','Polyorder',5);"

And I have 36 samples for label 1, and 28 samples for label -1. And when I use svmclassify with that "svmstrcut", it can work, and can classify the dataset.

I wonder why there are no support vectors and alpha in the structure "svmstruct" and how can the function svmclassify work with such a "svmstruct" ?

[Elisabetta Besana]

I've got the same problem! Were you able to find an answer? If so can you explain it to me? Thank you so much