Desperate help for using the B-spline function !!!

Hi guys,

I have a time-series (quarterly GDP) and I would like to smoothing it (de-trend) using the B-spline function.I think i need to use cubic curves.

Do you know how??

Many thanks

Answer 1

[Matt J]

If you have the Curve Fitting Toolbox, perhaps SPAPS will do what you need? There are also about a million spline tools on the File Exchange.

[Panty]

i have tried this toolbox...but I could not get the smooting line I would like.. Dont think that toolbox worked a lot. So I am looking for a more detailed method followed by an algorithm. I dont like built in functions a lot..

[Matt J]

Well, I don't think people are going to suggest a different method until we can see how you applied that method and understand why it didn't work. Since the tool was written exactly for that purpose, it's hard to see what a better proposal would be.

[Panty]

I found a spline fuction in the file exchange removing the noise from my time-series and geeting a smoothed line. Thank you for mentioning the file exchange option. I will accept you answer. However I would like to come back to you in case I face a problem. Many thanks Matt.