Problem 45854. Least Absolute Deviations (L1-norm) line fit - degree n

Created by jmac

Solve Later

This is a generalization of Problem 45851 for degree n
<https://www.mathworks.com/matlabcentral/cody/problems/45851-least-absolute-deviations-l1-norm-line-fit-degree-1>
- - - -
You are given two vectors X and Y (coordinates of observations on a plane), and a degree d of the underlying model. Return a row vector P with the d+1 coefficients of the best-fit polynomial, in the L1-norm sense. I.e., find P of degree d that minimizes sum( abs( Y - polyval(P,X) ) ) .
(compare your results with polyfit on the test suite!)

Solve

Solution Stats

11 Solutions
2 Solvers

Last Solution submitted on Apr 17, 2021

Last 200 Solutions

Problem Comments

3 Comments

3 Comments

Rafael S.T. Vieira on 18 Sep 2020

The problem with L1-norm is that It may have more than one possible solution. And the test suite should probably take this into account. (And the test suite also needs some fixing.)

PS: It's probably why people usually prefer the L2-norm instead of L1,L3 or LN-norm.

Are Mjaavatten on 17 Apr 2021

In Test 3, input variable d is set to 3 but left out in the call to LADfit. Thus is probably an oversight.

goc3 on 19 Apr 2021

@Are Mjaavatten: the function call in test 3 has been fixed to include all three inputs.

Solution Comments

Show comments

Problem Recent Solvers2

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 45854. Least Absolute Deviations (L1-norm) line fit - degree n

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers2

Suggested Problems

More from this Author10

Problem Tags

Community Treasure Hunt

Problem 45854. Least Absolute Deviations (L1-norm) line fit - degree n

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers2

Suggested Problems

More from this Author10

Problem Tags

Community Treasure Hunt

Players