# JSVMLearner with non linear kernel

ilaria_gori
Member Posts:

**15**Maven
Could you explain me why in jSVMLearner with non linear kernel, the vector w is calculated as linear combination of the training vectors, as in case of linear kernel? Why it is not simply given the function value which is sufficient to have the output?

thanks!

ilaria

thanks!

ilaria

0

## Answers

849Mavenhttp://rapid-i.com/rapidforum/index.php/topic,1455.msg5535.html#msg5535

15Mavenilaria

2,531UnicornI don't think haddock referred to the question in this topic. I rather believe he points to the solution I recommended: Reading the original paper.

Greetings,

Sebastian

15Mavenilaria

2,531Unicornthat's correct. So where did you see, that w was calculated in the wrong way? Did you see it in the source code or was it displayed within rapid miner?

Greetings,

Sebastian

15MavenI simply calculated it by myself, in order to see if I had understood the algorithm, and I remarked that Rapid Miner calculates it with the x_i and not with the phi(x_i). It's not a problem if you use only the confidence as output, but I thought It was interesting to point it out,

ilaria

849MavenNot sure Ilaria got due credit here for the close work, so let me be the first to commend it to you, top stuff!

2,531Unicornwhere exactly is the w shown in RapidMiner? I just want to take a closer look. If I remember correctly, the phi cannot be expressed for any kernel?

Greetings,

Sebastian

15Mavengreetings,

ilaria