print left view of binary tree

 

https://www.techiedelight.com/print-left-view-of-binary-tree/

heap python

 https://www.tutorialspoint.com/python_data_structure/python_heaps.htm

Heap is a special tree structure in which each parent node is less than or equal to its child node. Then it is called a Min Heap. If each parent node is greater than or equal to its child node then it is called a max heap. It is very useful is implementing priority queues where the queue item with higher weightage is given more priority in processing. A detailed discussion on heaps is available in our website here. Please study it first if you are new to head data structure. In this chapter we will see the implementation of heap data structure using python.

quick sort

 

https://stackabuse.com/quicksort-in-python/

some main data structures

 

stacks, hash maps, linked list, queues, trees, heaps, tries and graphs

stack

https://www.geeksforgeeks.org/stack-data-structure/

hash maps

https://www.geeksforgeeks.org/hash-map-in-python/

linked list

https://www.geeksforgeeks.org/linked-list-set-1-introduction/

queue

https://www.geeksforgeeks.org/queue-in-python/

tree

https://www.geeksforgeeks.org/binary-tree-data-structure/

heaps

https://www.geeksforgeeks.org/min-heap-in-python/

tries

https://www.geeksforgeeks.org/trie-insert-and-search/

graphs

https://www.geeksforgeeks.org/graph-data-structure-and-algorithms/

breadth first search

 breadth first search

https://www.geeksforgeeks.org/breadth-first-search-or-bfs-for-a-graph/

depth first search

 depth first search 

https://www.geeksforgeeks.org/depth-first-search-or-dfs-for-a-graph/

binary search

 binary search 

https://www.geeksforgeeks.org/binary-search/

quick sort

 quick sort

https://www.geeksforgeeks.org/quick-sort/

merge sort

 merge sort 

IDE recommendations

 there are a lot of IDEs. 

Eclipse and code::blocks are the two IDEs some programmers recommended to me. 

the IDEs I once used were PyCharm and atom. Some recommended sublime to me, an IDE similar to atom. 

Visual Studio Code is an IDE popular now. And it is free

https://code.visualstudio.com/

On linux, we used vim and emacs. They are editors. 

Notepad and Notepad ++ are text editors. 

what are bias and variance?

 bias and variance, basic definitions:

bias : it is the difference between average predictions and true values

variance: it is teh variability of our predictions, i.e. how spread out your model predictions are. 

https://www.cs.upc.edu/~belanche/Docencia/dm2/MATERIAL/1.%20ParamEst%20-%20Bias%20&%20Var/DMII-Class1.pdf

underfitting - high bias and low variance

overfitting - high variance and low bias 

How to find outliers

 

https://towardsdatascience.com/ways-to-detect-and-remove-the-outliers-404d16608dba

And we can use box plot to identify outliers. 

the data outside of the whiskers are outliers. 

boxplot(mpg~cyl,data=mtcars, main="Car Milage Data", xlab="Number of Cylinders", ylab="Miles Per Gallon")

roc curve, confusion matrix and everything about it

 roc curve, confusion matrix and everything about it

a few very useful data science blogs

 I once posted a post about 50 blogs for data science. 

https://easyprog99.blogspot.com/2018/04/top-50-data-science-blogs.html

And I found that 2 of them are very useful

1. analyticsvidhya.com

analyticsvidhya.com is a quite comprehensive blog for data science. There are some interesting data science posts on the website. besides that, there are courses, hackathons. And on hackthons, there are hackthons and the prize for them. And there are courses and webinars. 

2. https://towardsdatascience.com/

towarddatascience is a very inetersting blog for data science too. There are mainly posts about data science. 

3. infoq.com

infoq.com is a very informative blog for data, and software engineering. 

there are a lot of information there. 

Feature selction methods

 

https://www.analyticsvidhya.com/blog/2020/10/feature-selection-techniques-in-machine-learning/

F1 score is better than accuracy, why.

 

https://medium.com/analytics-vidhya/accuracy-vs-f1-score-6258237beca2