I try to demonstrate the use of splines in Bform. Nevertheless I am not sure about Bspline implementation in Matlab. In summary, for me there are 3 points:
- a spline looks like a hat-function, but smooth "spline".
- A family of splines tends to show maximum of weight sliding right as index of spline increases.
- multiplicity of end knots affect the slope and other derivatives, until, when a knot has multiplicity=order-1, to start at 1.0
This was the result below of "B-form" knots examples in Mathworks. Does anybody have experience with a ppform or break form ?
(Ich kann Deutsch lesen, aber mein Schreib ist eher begrenzt)
Code:
figure(2);
t = [.1 .4 .5 .80.9];
a = 1;
fnplt(spmak(t,a),2.5);
sp1=fnbrk(spmak(t,a),1:2)
t = [.1 .1 .4 .5 .8];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
t = [.1 .1 .1 .4 .5];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
t = [.1 .1 .1 .1 .4];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
t = [0.40.50.80.90.9];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
t = [0.50.80.90.90.9];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
t = [0.80.90.90.90.9];
a = 1;
hold on; fnplt(spmak(t,a),2.5);
When using interp1 with option 'spline' (not sure whether that's a B-spline), I notice and dislike a tendency towards overshooting and thus introducing artificial minima and maxima. Thus, I often prefer 'makima' as it looks quite smooth (e.g., smoother than 'pchip') but avoids what I just wrote.
MATLAB Answers is a larger forum and English is the main language there, so you may be better served posting English-language questions there.
Best wishes,
Harald
_________________
1.) Ask MATLAB Documentation
2.) Search gomatlab.de, google.de or MATLAB Answers
3.) Ask Technical Support of MathWorks
4.) Go mad, your problem is unsolvable ;)
Du kannst Beiträge in dieses Forum schreiben. Du kannst auf Beiträge in diesem Forum antworten. Du kannst deine Beiträge in diesem Forum nicht bearbeiten. Du kannst deine Beiträge in diesem Forum nicht löschen. Du kannst an Umfragen in diesem Forum nicht mitmachen. Du kannst Dateien in diesem Forum posten Du kannst Dateien in diesem Forum herunterladen
MATLAB, Simulink, Stateflow, Handle Graphics, Real-Time Workshop, SimBiology, SimHydraulics, SimEvents, and xPC TargetBox are registered trademarks and The MathWorks, the L-shaped membrane logo, and Embedded MATLAB are trademarks of The MathWorks, Inc.
RSS