(The below text version of the notes is for search purposes and convenience. See the PDF version for proper formatting such as bold, italics, etc., and graphics where applicable. Copyright: 2022 Retraice, Inc.)
Re93: The PriorityQueue Class, Part C
(Best-First-Search Part 12, AIMA4e pp. 73-74)
retraice.com
Examining Nodes and their handling by PriorityQueue.
The first nodein BFS is our problem initial state, and is returned as specified by the Nodeclass reprmethod; nodes passed to PriorityQueuemust be iterable so plain nodes and tuple nodes don't work, but dictionary nodes and string nodes do.
Air date: Saturday, 24th Dec. 2022, 4:00 PM Eastern/US.
Changing f and iterating a Node
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As an argument to PriorityQueue, node passed directly is not iterable, node as dictionary has one iteration, node as tuple is not iterable, node as string iterates through each character. When f returns tvalue, frontier.items returns [(, )] (whether node is passed as a list, as in Re92^1 , or a dictionary, as above); when f returns 'F-you', frontier.items returns [('F-you', )]. For each iteration, 'F-you' is assigned as the `score'.
Discovering the Node repr method
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The source of the format is the Node.__repr__method.
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Other sources to consult:
* https://docs.python.org/3/library/pdb.html
* Russell & Norvig (2020);
* Retraice (2022/12/14);
* Retraice (2022/12/15);
* Retraice (2022/12/16);
* Retraice (2022/12/17);
* Retraice (2022/12/18);
* Retraice (2022/12/19);
* Retraice (2022/12/20);
* Retraice (2022/12/21);
* Retraice (2022/12/22a);
* Retraice (2022/12/22b);
* Retraice (2022/12/23);
* http://aima.cs.berkeley.edu/figures.pdf;
* https://github.com/aimacode/aima-python/blob/master/search4e.ipynb;
* https://github.com/retraice/ReAIMA4e/.
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References
Retraice (2022/12/14). Re82: What is a problem? (BEST-FIRST-SEARCH Part 1, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re82Retrieved 15th Dec. 2022.
Retraice (2022/12/15). Re83: A Problem Instantiated (BEST-FIRST-SEARCH Part 2, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re83Retrieved 16th Dec. 2022.
Retraice (2022/12/16). Re84: A Node Instantiated (BEST-FIRST-SEARCH Part 3, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re84Retrieved 17th Dec. 2022.
Retraice (2022/12/17). Re85: The Details (BEST-FIRST-SEARCH Part 4, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re85Retrieved 18th Dec. 2022.
Retraice (2022/12/18). Re86: Code Reading (BEST-FIRST-SEARCH Part 5, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re86Retrieved 19th Dec. 2022.
Retraice (2022/12/19). Re87: The multimap Function, Part A (BEST-FIRST-SEARCH Part 6, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re87Retrieved 20th Dec. 2022.
Retraice (2022/12/20). Re88: The multimap Function, Part B (BEST-FIRST-SEARCH Part 7, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re88Retrieved 21st Dec. 2022.
Retraice (2022/12/21). Re89: The multimap Function, Part C (BEST-FIRST-SEARCH Part 8, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re89Retrieved 22nd Dec. 2022.
Retraice (2022/12/22a). Re90: The Map Class (BEST-FIRST-SEARCH Part 9, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re90Retrieved 23rd Dec. 2022.
Retraice (2022/12/22b). Re91: The PriorityQueue Class, Part A (BEST-FIRST-SEARCH Part 10, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re91Retrieved 24th Dec. 2022.
Retraice (2022/12/23). Re92: The PriorityQueue Class, Part B (BEST-FIRST-SEARCH Part 11, AIMA4e pp. 73-74). retraice.com.
https://www.retraice.com/segments/re92Retrieved 24th Dec. 2022.
Russell, S., & Norvig, P. (2020). Artificial Intelligence: A Modern Approach. Pearson, 4th ed. ISBN: 978-0134610993. Searches:
https://www.amazon.com/s?k=978-0134610993
https://www.google.com/search?q=isbn+978-0134610993
https://lccn.loc.gov/2019047498
Footnotes
^1 Retraice (2022/12/23).
