Effacer les filtres
Effacer les filtres

Possible to "expand" function handle?

1 vue (au cours des 30 derniers jours)
dm
dm le 18 Fév 2012
I've written a function that returns a function handle to a Lagrange polynomial L(x):
function L = lagrange(xv,yv)
% make sure xv and yv are row vectors
xv = xv(:);
yv = yv(:);
% check for equal dimensions
if size(xv) ~= size(yv)
error('xv and yv must be of same dimensions');
end
% number of points
n = length(xv);
% initialize to zero
L = @(x)0;
for k = 1:n
l = @(x)1; % initialize k'th basis polynomial
for m = 1:n
if k ~= m % if k different from m, calculate basis
l = @(x)(l(x).*(x-xv(m))/(xv(k)-xv(m)));
end
end
L = @(x)(L(x)+yv(k).*l(x)); % perform linear combination
end
It seems to work as I want it to (calling L(4), or whatever, produces the correct result), but if I type L in the command line, Matlab prints "L = @(x)(L(x)+yv(k).*l(x))".
Is it possible to get the complete function printed out? I.e., if my yv vector stems from the function x^3, then the Lagrange polynomial should be 6x^2-11x+6, but I can't figure out how to get this printed out; is it posible?
best regards
dm

Réponse acceptée

Walter Roberson
Walter Roberson le 18 Fév 2012
Sorry, no it is not.
  2 commentaires
dm
dm le 18 Fév 2012
Oh well. Not a big deal, was just curious if there could be something that I had overlooked.
Walter Roberson
Walter Roberson le 19 Fév 2012
You may wish to consider using symbolic expressions instead.

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Polynomials dans Help Center et File Exchange

Community Treasure Hunt

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

Start Hunting!

Translated by