New answers tagged

0

In the example you link to, the sigma parameter has got nothing to do with the clustering; it is only used to generate sample data for illustration. It defines the spread of cluster elements around the (pre-defined) centroid of each cluster. This is done for demonstration only: you generate clusters which you know exist, and then check that the cluster ...


0

More comments in addition to the accepted answer. The OP says the two algorithms have different value functions. This is actually not precise and may be the source of confusion. In particular, only in the policy iteration algorithm, the value of $v$ is the state value function, which is the solution to the Bellman equation. However, the value of $v$ in value ...


0

Value iteration (VI) is a truncated version of Policy iteration (PI). PI has two steps: the first step is policy evaluation. That is to calculate the state values of a given policy. This step essentially solves the Bellman equation $$v_\pi=r_\pi+\gamma P_\pi v_\pi$$ which is the matrix vector form of the Bellman equation. I assume that the basics are ...


0

The Policy Iteration algorithm (given in the question) is model-based. However, note that there exist methods that fall into the Generalized Policy Iteration category, such as SARSA, which are model-free. From what I understand, policy iteration is a model-free algorithm Maybe this was referring to generalized policy iteration methods. (Answer based on ...


1

The paper Comparison between genetic algorithms and particle swarm optimization (1998, by Eberhart and Shi) does not really answer the question of when to use one over the other (this may be an open question), but at least it provides a comparison of how the methods work and what could affect their performance (i.e. which parameters or operators they use, ...


0

Closed Loop Network Step-Ahead Prediction Network The function CLOSELOOP replaces the feedback input with a direct connection from the output layer. Step-Ahead Prediction Network also known as removedelay function helps to remove delay to neural network’s response In Closed loop networks, its own predictions become the feedback inputs. targets with a delay ...


0

Value Iteration Vs Policy Iteration Below is the list of differences & similarities between value iteration and policy iteration Differences Value Iteration Policy Iteration Execution starts with a random value function random policy Algorithm simpler complex Computation costs more expensive cheaper Execution time Slower Faster No of Iterations to ...


0

It depends on what you consider to be fake news: if you want to say if a news story tells truth, or if you want to detect if a news story uses language that is typical for fake news. Probably the major criterion is that the content news story is in contradiction with the state of affairs. If this is your criterion of fakeness, you need to do some sort of ...


Top 50 recent answers are included