Proj6: Tau

[Everett Kotler]

I am a little confused about tau. It is suppose to be a vector or a
constant? The calcuation uses w'c, w'c* and f which are vectors, but C is
just a constant.

Thanks,

Everett

[Daniel Ritchie]

Tau is a scalar. Let's look at the formula for it (we'll leave out the
min part for simplicity's sake):

Tau = ((Wy' - Wy) * f + 1) / (2 * L2norm(f)^2)

(Wy' - Wy) is a vector, so (Wy' - Wy) * f + 1 is a scalar (* here is the
dot product). The L2norm of a vector is also a scalar, so the whole
expression 2 * L2norm(f)^2 is a scalar. Dividing a scalar by a scalar
gives you a scalar, so the whole expression evaluates to a scalar.

I hope that helps.

Post by Everett Kotler
I am a little confused about tau. It is suppose to be a vector or a
constant? The calcuation uses w'c, w'c* and f which are vectors, but C
is just a constant.
Thanks,
Everett

[Everett Kotler]

Ahh I get it now. Thanks

Tau is a scalar. Let's look at the formula for it (we'll leave out the min
Tau = ((Wy' - Wy) * f + 1) / (2 * L2norm(f)^2)
(Wy' - Wy) is a vector, so (Wy' - Wy) * f + 1 is a scalar (* here is the
dot product). The L2norm of a vector is also a scalar, so the whole
expression 2 * L2norm(f)^2 is a scalar. Dividing a scalar by a scalar
gives you a scalar, so the whole expression evaluates to a scalar.
I hope that helps.

Post by Everett Kotler
I am a little confused about tau. It is suppose to be a vector or a
constant? The calcuation uses w'c, w'c* and f which are vectors, but C
is just a constant.
Thanks,
Everett