Notschko hat geschrieben:by definition C is the weight for \(\xi_i\). Does this mean, if C=0 the result will be the same as in Problem1A? (...) Still, I'm getting some different values for w and b compared to 1A even if C is 0

You should not consider

*C* to be a weight. It just describes the trade-off between the penalties of the slack variables and the margin which holds for all variables. I can't give you the answer right away, but you should probably try some different settings and then take the resulting change of margins into consideration. Varying

*C* you will get a feeling about its influence.

If you find the right

*C* you will end up with something pretty similar to the results of a).

Notschko hat geschrieben:Also, my values for \(\xi_i\) are greater than 0 for C=0

The slack variables are

\(\xi_i \ge 0\) per definition. If you have

\(\xi_i = 0\), it means the associated point is on the correct side of the margin. On the other hand, if

\(\xi_i > 0\) then

\(\xi_i = |t_i - y(x_i)|\) holds and the associated point is not on the correct side. In this case there are two options: Either the slack variable is > 1 or the slack variable is < 1 and both cases correspond to the sides of the decision boundary, respectively. In other words: The result of your optimization should never give you negative slack variables! If it does, there is something going wrong..

Notschko hat geschrieben:... and I don't know if this is right and what to do with these values.

Easy answer: Nothing! They are just help variables required for the optimization, you can discard them afterwards..

EDIT: ahhhh too late