def kernel_weighted_degree_string_modular (fm_train_dna=traindat,fm_test_dna=testdat,degree=20):
from shogun.Features import StringCharFeatures, DNA
from shogun.Kernel import WeightedDegreeStringKernel, MSG_DEBUG
feats_train=StringCharFeatures(fm_train_dna, DNA)
#feats_train.io.set_loglevel(MSG_DEBUG)
feats_test=StringCharFeatures(fm_test_dna, DNA)
kernel=WeightedDegreeStringKernel(feats_train, feats_train, degree)
from numpy import arange,double
weights=arange(1,degree+1,dtype=double)[::-1]/ \
sum(arange(1,degree+1,dtype=double))
kernel.set_wd_weights(weights)
#from numpy import ones,float64,int32
#kernel.set_position_weights(ones(len(fm_train_dna[0]), dtype=float64))
km_train=kernel.get_kernel_matrix()
kernel.init(feats_train, feats_test)
km_test=kernel.get_kernel_matrix()
#this is how to serializate the kernel
#import pickle
#pickle.dump(kernel, file('kernel_obj.dump','w'), protocol=2)
#k=pickle.load(file('kernel_obj.dump','r'))
return km_train, km_test, kernel
