These functions from the library are not bound as ruby methods:
void svm_get_labels(const struct svm_model *model, int *label);
double svm_get_svr_probability(const struct svm_model *model);
void svm_destroy_param(struct svm_parameter *param);
The model holds reference to the parameters struct, so it's not obvious when it's safe to use.
int svm_check_probability_model(const struct svm_model *model);