Asignment 1 Problem 2

[X-Out]

Hi,

I'm confused because of this exercise. Are we supposed to answer question "Part A" and B or the questions below starting with "(10 points)"?

The problem is in Part A your asking about an univariat distribution and a statement about a condition for the decision boundary is asked. But below this task is about the bivariat distribution and here we are only looking for the shape of the boundary but no conditions.

Thanks for your answers

[sroth]

You have to do both parts:

The questions in the bullet points (with 10 points each) belong to part B, i.e. the bivariate case.
Part A on the other hand (20 points) is about univariate Gaussians; only the tasks described in the 6 lines of text starting at "Part A" are relevant for this problem.

Hope that clarifies it,
Stefan Roth

[xAx]

Part B, Task 1 asks me to "plot these distributions". Which ones exactly? For example: either p(x | C_1) or p(x | C_1) * p(C_1)?

[sroth]

You have two options (both are fine):
* If you plot them into separate coordinate systems (e.g. with subplot), then either p(x|C_1) or p(x | C_1) p(C_1) is fine, since the prior just rescales the function.
* If you plot both into the same coordinate system (i.e. with "hold"), you should use the joint, e.g. p(x | C_1) p(C_1).

Stefan Roth