Possible to "expand" function handle?
1 view (last 30 days)
Show older comments
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
0 Comments
Accepted Answer
More Answers (0)
See Also
Categories
Find more on Polynomials in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!