Prototypical Networks Protonets

Tags: #machine learning #meta learning

Equation

$$c_{k}=\frac{1}{|S_{k}|}\sum_{(x_{i},y_{i}) \in S_{k}} f_{\phi}(x) \\ p_{\phi}(y=k|x)=\frac{\exp(-d(f_{\phi}(x), c_{k}))}{\sum_{k^{'}} \exp(-d(f_{\phi}(x), c_{k^{'}})} \\\min J(\phi)=-\log p_{\phi}(y=k|x)$$

Latex Code

                                 c_{k}=\frac{1}{|S_{k}|}\sum_{(x_{i},y_{i}) \in S_{k}} f_{\phi}(x) \\ p_{\phi}(y=k|x)=\frac{\exp(-d(f_{\phi}(x), c_{k}))}{\sum_{k^{'}} \exp(-d(f_{\phi}(x), c_{k^{'}})} \\\min J(\phi)=-\log p_{\phi}(y=k|x)
                            

Have Fun

Let's Vote for the Most Difficult Equation!

Introduction

Equation



Latex Code

            c_{k}=\frac{1}{|S_{k}|}\sum_{(x_{i},y_{i}) \in S_{k}} f_{\phi}(x) \\ p_{\phi}(y=k|x)=\frac{\exp(-d(f_{\phi}(x), c_{k}))}{\sum_{k^{'}} \exp(-d(f_{\phi}(x), c_{k^{'}})} \\\min J(\phi)=-\log p_{\phi}(y=k|x)
        

Explanation

Prototypical networks compute an M-dimensional representation c_{k} or prototype, of each class through an embedding f_{\phi}(.) with parameters \phi. Each prototype is the mean vector of the embedded support points belonging to its class k. Prototypical networks then produce a distribution over classes for a query point x based on a softmax over distances to the prototypes in the embedding space as p(y=k|x). Then the negative log-likelihood of J(\theta) is calculated over query set.

Related Documents

Related Videos




Prototypical Networks as Mixture Density Estimation

Bregman divergences



            d_{\phi}(z,z^{'})=\phi(z) - \phi(z^{'})-(z-z^{'})^{T} \nabla \phi(z^{'})
        

Mixture Density Estimation


            p_{\phi}(y=k|z)=\frac{\pi_{k} \exp(-d(z, \mu (\theta_{k})))}{\sum_{k^{'}} \pi_{k^{'}} \exp(-d(z, \mu (\theta_{k})))}
        

Explanation

The prototypi- cal networks algorithm is equivalent to performing mixture density estimation on the support set with an exponential family density. A regular Bregman divergence d_{\phi} is defined as above. \phi is a differentiable, strictly convex function of the Legendre type. Examples of Bregman divergences include squared Euclidean distance and Mahalanobis distance.

Discussion

Comment to Make Wishes Come True

Leave your wishes (e.g. Passing Exams) in the comments and earn as many upvotes as possible to make your wishes come true


  • Shawn Bell
    Here's to passing this test, let's make it happen!
    2023-05-20 00:00

    Reply


    Evelyn Nelson reply to Shawn Bell
    Nice~
    2023-05-23 00:00:00.0

    Reply


  • Donald White
    Desperately wanting to pass this exam.
    2023-01-14 00:00

    Reply


    Gary Adams reply to Donald White
    You can make it...
    2023-01-21 00:00:00.0

    Reply


  • Elizabeth Jones
    The only thing I want is to pass this test.
    2024-03-13 00:00

    Reply


    Jessica Davis reply to Elizabeth Jones
    You can make it...
    2024-03-14 00:00:00.0

    Reply