Markov Decision Processes 1 - Value Iteration | Stanford CS221: AI (Autumn 2019)

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@nsubugakasozi7101 9 ай бұрын

This lecturer is world class...and this is also the most confident live coding I have seen in a while...she is really really good. Universities are made by the lecturers...not so much the name

@MLRTrytonix13 Ай бұрын

live coding? its a video lmaoo

@foufayyy 2 жыл бұрын

thank you for posting this. MDPs were really confusing and this lecture really helped me understand it clearly.

@-isotope_k 2 жыл бұрын

Yes this is very very confusing topic

@pirouzaan Жыл бұрын

this was by far the most impressive lecture with live coding that I had seen! I am leaving this virtual lecture room with awe and respect...

@meharjeetsingh5256 Жыл бұрын

this teacher is really really good. I wish you were at my Uni so that i could enjoy machine learning

@dawn-of-newday 2 жыл бұрын

I wanna appreciate this lecture, its good. i had a difficult time and mental block for this topic. I wanna say thanks for all ur efforts.

@vishalsunkapaka7247 2 жыл бұрын

professor is so talented can’t say anything just feared over her, can’t take anymore

@WojciechBrzoska-w2s Жыл бұрын

It was my n-th iteration of MDP -where n>10 but using terminology of of MDP my knowlege finnally started to converge to proper direction. Thank you for the lecture🙂

@iiilllii140 2 жыл бұрын

Thank you for this lecture and the course order. The past lectures about search problems really help you to better understand MDPs.

@seaotterlabs1685 2 жыл бұрын

Amazing lecture! I was having trouble finding my footing on this topic and now I feel I have a good starting point of the concepts and notations! I hope Professor Sadigh teaches many more AI topics!

@stanfordonline 2 жыл бұрын

Excellent, thanks for your feedback!

@ibenlhafid 2 жыл бұрын

Mmmm

@ibenlhafid 2 жыл бұрын

@snsacharya1737 Жыл бұрын

At 29:36, a policy is defined as a one-to-one mapping from the state space to the action space; for example, the policy when we are in station-4 is to walk. This definition is different compated to the one made in the classic RL book by Sutton and Barto; they define a policy as "a mapping from states to probabilities of selecting each possible action." For example, the policy when we are in station-4 is a 40% chance of walking and 60% chance of taking the train. The policy evaluation algorithm that is presented in this lecture also ends up being slightly different by not looping over the possible actions. It is nice of the instructor to highlight that point at 55:45

@aojing 10 ай бұрын

Action is determined from the beginning independent of states in this class...This will mislead beginners to confuse Q and V, as by this definition @47:20. In RL, we take action by policy, which is random and can be learned/optimized by iterating through episodes, i.e., parallel worlds.

@chanliang5725 Жыл бұрын

I was lost on the MDP. Glad I find this awesome lecture clears all concepts in MDP! Very helpful!

@shaheerkashif5908 21 күн бұрын

Professor Sadigh, the legend you are

@joshuat6124 9 ай бұрын

Thank you professor! I learnt to much from this, especially the live coding bits.

@muheedmir7385 2 жыл бұрын

Amazing lecture, loved every bit of it

@quannmtt3110 Жыл бұрын

Thanks for the awesome lecture. Very good job at explanation by the lecturer.

@tosinadekunle646 2 ай бұрын

Gamma is to avoid the neutrality of using 1 in the computation of Utility (The Return). 0.9^3 is not neutral compared to 1^3 which is neutral.

@yesodabhargava8776 2 жыл бұрын

This is an awesome lecture! Thank you so much.

@adityanjsg99 2 жыл бұрын

A thorough lecture!!

@carlosloria-saenz6760 Жыл бұрын

Great videos, thanks!. At time 47:20 on the board a small typo, I guess it should be: V_{\pi}(s) = Q_{\pi}(s, \pi(s)) if s not the end state.

@ammaraboklam2487 2 жыл бұрын

Thank you very much This is really great lecture it's really helpful

@stanfordonline 2 жыл бұрын

Hi Ammar, glad it was helpful! Thanks for your feedback

@sukhjinderkumar2723 2 жыл бұрын

Great Lecture, Thank you Professor :)

@alemayehutesfaye463 Жыл бұрын

Thank you for your interesting lecture this lecture really helped me to understand it well.

@stanfordonline Жыл бұрын

Hi Alemayehu, thanks for your comment! Nice to hear you enjoyed this lecture.

@alemayehutesfaye463 Жыл бұрын

@@stanfordonline Thanks for your reply. I am following you from Ethiopia and had interest on the subject area. Would you mind in suggesting best texts and supporting video's which may be helpful to have in-depth knowledge in the areas of Markov Processes and decision making specially related to manufacturing industries?

@vimukthirandika872 2 жыл бұрын

Thank for amazing lecture!

@HarshvardhanKanthode 2 жыл бұрын

Where are all the comments?

@mukhtarabdullahi1164 Ай бұрын

Amazing lecture. Thanks prof

@aojing 10 ай бұрын

@47:20 the definition of Q function is not right and confuses with Value function. Specifically, take immediate reward R out of summation. The reason is Q function is to estimate the value of a specific Action beginning with current State.

@aojing 10 ай бұрын

or we may say the Value function here is not properly defined without considering policy, i.e., by taking action independent of states.

@karimdarwich1913 6 ай бұрын

How can I choose the "right" gamma for my problem? Like how can I know that the gamma I choose is good or not ?

@marzmohammadi8739 2 жыл бұрын

لذت بردم خانم صدیق. کیف کردم .. مممنووونننن

@RojinaPanta1 Жыл бұрын

would not removing constraint increase search space making computationally inefficent?

@FalguniDasShuvo 4 ай бұрын

Great!👍

@farzanzeinali7398 2 жыл бұрын

The transportation example has a problem. The states are discrete. If you take the tram, the starting state equals 1, and with state*2, you will never end up in state=3. Let's assume the first action was successful, therefore, the next state is 2. If the second action is successful too, you will be end up in state = 4. you will never end up in state = 3.

@faiber49 2 ай бұрын

That is why she used this line of code when the actions where defined: if state * 2

@alphatensor Жыл бұрын

Thanks for the good lecture

@Amit1994-g9i 2 жыл бұрын

FYI I'm a theoretical physics major, and I have no business in CS and whatsoever

@msfallah 2 жыл бұрын

I think the given definition for value-action function (Q(s, action)) is not correct. In fact value function is the summation of value-action functions over all actions.

@camerashysd7165 8 ай бұрын

Wow this account crazy 😮

@vikasshukla831 2 жыл бұрын

Can in the Dice Game If choose to stay for the step 1 and then quit in the second stage: will I get 10 dollars if I choose to quit in the stage 2? Because If I am lucky enough to go to second stage i.e the dice doesn't roll 1,2 then I am in the "In" state and by the diagram I have option to quit which might give me 10 dollar but for that I should have success in stage 1. Then the best strategy might change. Let know what are your comments?

@fahimullahkhan775 2 жыл бұрын

You are right according to the figure and flow of the states, but from the scenario ones get the perception that ones has a chance to either quit at the start or stay in the game.