How I can code this Nonuniform Series?

4 Ansichten (letzte 30 Tage)
mohamad hoseini
mohamad hoseini am 10 Okt. 2018
Bearbeitet: mohamad hoseini am 12 Okt. 2018
Hi all,
I have a problem in coding of series below:
from n=0 & P0(x)=1. I used handle function in a for loop but I couldn't to save the handle function at the end of each iteration. I appreciate you if you could help me on this problem.
Thanks
  4 Kommentare
Torsten
Torsten am 11 Okt. 2018
Do these recursively defined polynomials have a name ?
Then maybe googling this name together with "matlab" will give you hints on how to efficiently calculate them.
mohamad hoseini
mohamad hoseini am 12 Okt. 2018
Bearbeitet: mohamad hoseini am 12 Okt. 2018
This is gram-schmidt orthogonalization or process. I have the symbolic math toolbox on my MATLAB. I'll post my code below despite dear "Dimitris Kalogiros" posted a perfect answer to my question.

Melden Sie sich an, um zu kommentieren.

Akzeptierte Antwort

Dimitris Kalogiros
Dimitris Kalogiros am 11 Okt. 2018
Bearbeitet: Dimitris Kalogiros am 11 Okt. 2018
Provided that you can use symbolic math toolbox, I suggest the following:
close all; clc; clearvars;
syms n x Pn(x)
% first N polynomials
N=5;
f{N}=0;
% definition for n=0
Pn(x)=1;
f{1}=Pn(x);
% calculation from n=1 up to n=N
for n=1:N
Pn(x)=x^n;
for k=1:n
Pn(x)=Pn(x)- ( int((x^n)*f{k},x,-1,1) / int(f{k}^2,x,-1,1) )* f{k} ;
end
%store next polynomial
f{n+1}=Pn(x);
end
%display all calculated polynomials
for k=0:N
fprintf(' for n = %d ', k);
disp(f{k+1})
end
If you run it , lets say , to calculate P1(x), P2(x),...,P5(x) , you'll get something like this:
The "tip" here is to use the cell array f{}, in order to store all Pn(x) polynomials.
  2 Kommentare
Walter Roberson
Walter Roberson am 11 Okt. 2018
Bearbeitet: Walter Roberson am 11 Okt. 2018
Alternatively you could phrase it as P{n+1}(x). Which is to say that you can use a cell array of function handles to solve the coding, without using symbolic toolbox.
This is a situation where I would want to analyze to see whether memoize() is appropriate.
mohamad hoseini
mohamad hoseini am 12 Okt. 2018
That works completely right dear Dimitris. I appreciate you for sharing your knowledge on my question. I was not familiar with this toolbox before and I know something valuable now.

Melden Sie sich an, um zu kommentieren.

Weitere Antworten (0)

Community Treasure Hunt

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

Start Hunting!

Translated by