search for: quintic

Dear all, I'm trying to use the Pspline add-on package to fit a quintic spline (norder =3), but I keep running into a Singularity error. > traj.spl <- smooth.Pspline(time, x, norder=3 ) Error in smooth.Pspline(time, x, norder = 3) : Singularity error in solving equations > Playing around with the other parameters produces an "unused arguments" e...

...228353 0.5752811 0.5319524 0.4957381 0.4695269 0.4562077 0.4586691 0.4798001 9 10 0.5224893 0.5896255 and lets extrapolate a bit: > predict(mmn[[3]],newdata=data.frame(x=c(9,10,11))) 1 2 3 0.5224893 0.5896255 0.6840976 now let's to it for cubic to quintic: > mmn = lmn(d,3:5) check the cubic: > predict(mmn[[3]]) 1 2 3 4 5 6 7 8 0.6228353 0.5752811 0.5319524 0.4957381 0.4695269 0.4562077 0.4586691 0.4798001 9 10 0.5224893 0.5896255 - thats the same as last tim...

...954198,4.540740741,3.686567164,2.8,2.968253968,3.517730496) Pipits is the response variable (it is the number of birds counted at each survey site in each year) and year is the independent variable. If you plot it in R (plot(year,piproute,pch=19)), you'll see that the relationship looks like a quintic polynomial. Initially I was trying to fit this curve using an iterative equation, but it's not working. I suspect that the curve-fitting equation itself is inappropriate (it's a modified version of the logistic growth equation). Now what I'd like to do is identify the 3 break/inflectio...

Hi, I would like like to compute first and second derivative from numerical data. I hoped I could compute a spline object from the data (that works), and then compute the derivative from that spline objects, but I couldn't find anything like that. Does somebody know how to get numerical derivatives? Oliver -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-

...f raw data, because differencing raw data amplifies noise, while appropriate smooths eliminate much of the noise, leaving you with what you most want. Ramsay and Silverman (2005) Functional Data Analysis, 2nd ed. (Springer) suggest that if you want a second derivative, it is often wise to use quintic splines, because then the second derivative are cubic splines. (The first derivative of a spline of order k is a spline of order k-1.) An example is provided in Figure 1.2 of Ramsay, Hooker and Graves (2009) Functional Data Analysis with R and Matlab (Springer). However, you don't...