angular data spline interpolation
5 visualizaciones (últimos 30 días)
Mostrar comentarios más antiguos
mukesh bisht
el 22 de Ag. de 2021
Comentada: darova
el 23 de Ag. de 2021
Hi, I have the following query using spline interpolation for angular data. The code attached below is from matlab documentation:
x = pi*[0:.5:2];
y = [0 1 0 -1 0 1 0;
1 0 1 0 -1 0 1];
pp = spline(x,y);
yy = ppval(pp, linspace(0,2*pi,101));
plot(yy(1,:),yy(2,:),'-b',y(1,2:5),y(2,2:5),'or')
axis equal
This code gives the closed piecewise polynomial for circle of radius 1unit. Now if I calculate the value of plynomial for a given query point, it doesnt give me the correct answer. why??
For ex: xq = 0; yq = ppval(pp,xq);
It gives yq = [1;0] but it should be yq = [1,-1];
1 comentario
Julius Muschaweck
el 23 de Ag. de 2021
If you think my answer is correct, please make it the "accepted answer".Thanks
Respuesta aceptada
Julius Muschaweck
el 22 de Ag. de 2021
Your x has five values, your y has seven values. This is a mismatch.
I think you should use
y = [0 1 0 -1 0;
1 0 -1 0 1];
and when you do that,
xq = 0; yq = ppval(pp,xq);
gives you [0;1] as it should. Your "circle" looks more triangular, but that's ok since the sine is badly approximated by the spline with only 5 support points.
6 comentarios
Más respuestas (0)
Ver también
Categorías
Más información sobre Interpolation en Help Center y File Exchange.
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!