Re: [R] Problem with Princurve

2011-06-07 Thread guy33
guy33 wrote: > > As suggested above, specifying useful starting points definitely helps in > the case of: > > x <- seq(0,2*pi, length=1000) > x <- cbind(x/(2*pi), sin(x)) > fit1 <- principal.curve(x, plot = TRUE, trace = TRUE, maxit = 100, start = > cbind(sort(x[,1]), rep(1, nrow(x > > >

Re: [R] Problem with Princurve

2011-06-07 Thread guy33
As suggested above, specifying useful starting points definitely helps in the case of: x <- seq(0,2*pi, length=1000) x <- cbind(x/(2*pi), sin(x)) fit1 <- principal.curve(x, plot = TRUE, trace = TRUE, maxit = 100, start = cbind(sort(x[,1]), rep(1, nrow(x Interestingly, I find that if you sim

Re: [R] Problem with Princurve

2011-05-23 Thread Gavin Simpson
lp-boun...@r-project.org] On Behalf > Of Gavin Simpson [gavin.simp...@ucl.ac.uk] > Sent: Monday, May 23, 2011 8:27 AM > To: guy33 > Cc: r-help@r-project.org > Subject: Re: [R] Problem with Princurve > > On Thu, 2011-05-19 at 06:43 -0700, guy33 wrote: > > Hey all, &g

Re: [R] Problem with Princurve

2011-05-23 Thread Henrik Bengtsson
hm is quite sensitive to > starting values.  Is this behavior expected or is there some flaw in the > algorithm? > > Ravi. > > > From: r-help-boun...@r-project.org [r-help-boun...@r-project.org] On Behalf > Of Gavin Simpson [gavin.simp

Re: [R] Problem with Princurve

2011-05-23 Thread Ravi Varadhan
Of Gavin Simpson [gavin.simp...@ucl.ac.uk] Sent: Monday, May 23, 2011 8:27 AM To: guy33 Cc: r-help@r-project.org Subject: Re: [R] Problem with Princurve On Thu, 2011-05-19 at 06:43 -0700, guy33 wrote: > Hey all, > > I can't seem to get the princurve package to produce correct results, ev

Re: [R] Problem with Princurve

2011-05-23 Thread Gavin Simpson
On Thu, 2011-05-19 at 06:43 -0700, guy33 wrote: > Hey all, > > I can't seem to get the princurve package to produce correct results, even > in the simplest cases. For example, if you just generate a 1 period > noiseless sine wave, and ask for the principal curve and plot, the returned > curve is

Re: [R] Problem with Princurve

2011-05-19 Thread David Winsemius
On May 19, 2011, at 9:43 AM, guy33 wrote: Hey all, I can't seem to get the princurve package to produce correct results, even in the simplest cases. For example, if you just generate a 1 period noiseless sine wave, and ask for the principal curve and plot, the returned curve is clearly w

[R] Problem with Princurve

2011-05-19 Thread guy33
Hey all, I can't seem to get the princurve package to produce correct results, even in the simplest cases. For example, if you just generate a 1 period noiseless sine wave, and ask for the principal curve and plot, the returned curve is clearly wrong (doesn't follow the sine wave). Here's my cod