I know that y(2) is -1.5 and where I went wrong was in xx and yy i just dont really know how to do it at all lol
How do I properly plot Lagrange Interpolation ?
12 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Yo mama
am 20 Mär. 2020
Kommentiert: Yo mama
am 20 Mär. 2020
x=[-2 1 3 5 ];
y=[0 -1.8 -1.2 -1.6];
sum=0;
for i=1:length(x)
p=1;
for j=1:length(x)
if j~=i
c = poly(x(j))/(x(i)-x(j));
p = conv(p,c);
end
end
term = p*y(i);
sum= sum + term;
end
disp(sum);
xx = linspace(min(sum), max(sum), 100); % Bunch of new samples for a smoother plot
yy = sum(1)*xx.^3 + sum(2)*xx.^2 + sum(3)*xx + sum(4);
plot(x, y, '-s')
hold on
plot(xx,yy,'-r')
%plot(sum,'-o')
xlabel('x'), ylabel('y'), title('Lagrange Polynomial Fit ')
legend('Data Collection', 'Lagrange Polynomial Fit', 'Location', 'northeast')
Akzeptierte Antwort
Sriram Tadavarty
am 20 Mär. 2020
Hi Daniel,
Update the variable xx with the limits of x rather than sum, and you would see a clear plot. Something like this
xx = linspace(-2, 5, 1000); % Bunch of new samples for a smoother plot
% -2 and 5 are minimum and maximum values of x
Hope this helps.
Regards,
Sriram
3 Kommentare
Sriram Tadavarty
am 20 Mär. 2020
Bearbeitet: Sriram Tadavarty
am 20 Mär. 2020
May i know what are you referring here about plots not working, xx has just increased it's span.
It would give a plot as attached.
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Interpolation finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!