Some quesitions about RBF kernel and ranksvm

Hi guys, I have some questions about ranksvm and RBF kernel. Thanks for all your help.

1. The RBF kernel function is :

2. how can we calculate this function

3.The function in question 2 is used in this function. I donot know how to calculate the question 2.

This is a kernel based ranksvm. I understand the algorithm, but I donot understand how to transfer the x_i into phi(x_i).

Answer 1

[HC Song]

I find out the solutions . In Algorithms for ranking with SVMs, the section 6.3 disscussed this issue and one solution was provided. I code the algorithms and test it. the result is correct.

[uday madappa]

Can you please share the code. Thanks in advance.