Feature evaluation criteria

-
Feature sub-setting is through selection or elimination.


We look approximation algorithm:

  1. Feature evaluation criteria.
  2. Feature are ranked.
  3. Select top 'd' features.
1 and 2 could be independent of learning algorithm (unsupervised).
Example: Filtering algorithm (filters)/model.
Ex: Big data, independent of class label. Then it is called as unsupervised feature selection (classification).

1 and 2 could be dependent of learning algorithm (supervised).
Example: Wrapper algorithm (wrappers)/model.
Ex: Small data, class label/class information dependent. Then it is called as supervised feature selection (clustering).

Popular posts from this blog

RESUME 2025 AUG

-
MY RESUME 01/08/2025 ========================================================================= PDF version of my resume 1/AUGUST/2025 https://drive.google.com/file/d/1VkKwQNF-m9w2_FiJ7FT0phNeY9MuQWl6/view?usp=sharing ========================================================================== DOC Version of my resume 1/AUGUST/2025 https://docs.google.com/document/d/108WiLLDZo-9l1sgaSSutkQZaE8iIma3g/edit?usp=drive_link&ouid=111069544115391871585&rtpof=true&sd=true ==========================================================================
Read more

Difference between sequential allocation and linked allocation

-
Sequential allocation Linked allocation Static in nature. Dynamic in nature. Required to estimate the capacity of the structure. Not required. All memory locations are consecutive in nature. Therefore computed addressing is possible. Need not be. It works based on pointer addressing. Two logically adjacent elements are also physically adjacent. Not necessarily. Therefore each data element should hold the address of its next logically adjacent element. This can be a bottleneck problem. Support direct accessing or addressing of data. Sequential addressing or accessing of data. In a strict sense, deletion, and insertion operations are prohibited. Insertion and deletion operation is possible and is straight forward. Splitting and merging operation is also prohibited. However, these can be realized by data movement with extra memory allocation. This can be sometimes a bottleneck problem. Possible and straight forw...
Read more

Implementing queue datastructure using c program.

-
/*queue*/ #include<stdio.h> #include<stdlib.h> #define queue_size 5 int c,item,f,r,q[10]; void ri() {     if(r==queue_size-1)     {         printf("queue overflow\n");         return;     }     r=r+1;     q[r]=item; } void fd() {     if(f>r)     {         printf("queue underflow\n");         return;     }     printf("the element deleted is %d",q[(f)++]);     if(f>r)f=0,r=-1; } void display() {     int i;     if(f>r)     {         printf("queue is empty\n");         return;     }     printf("contents of the...
Read more