A user defined custom kernel is assigned in this example, for which only the lower triangle 
may be given (set_triangle_kernel_matrix_from_triangle) or 
a full matrix (set_full_kernel_matrix_from_full), or a full matrix which is then internally stored as a 
triangle (set_triangle_kernel_matrix_from_full). Labels for the examples are given, a svm is trained and 
the svm is used to classify the examples. 

