public Kernel(int l, svm_node[][] x_, svm_parameter param) {
this.kernel_type = param.kernel_type;
this.degree = param.degree;
this.gamma = param.gamma;
this.coef0 = param.coef0;
x = (svm_node[][])x_.Clone();
if (kernel_type == svm_parameter.RBF) {
x_square = new double[l];
for (int i = 0; i < l; i++)
x_square[i] = dot(x[i], x[i]);
} else x_square = null;
}