[R] how to allign data

[PIKAL Petr]

Hi Jim

Thanks for your function, however I either do not understand its purpose or I did not explained my aim correctly.

with segmented package I could find x value for break in slope
fit<-lm(y1~x)
segmented(fit, seg.Z=~x)
Estimated Break-Point(s):
psi1.x
 20.77
fit<-lm(y2~x)
segmented(fit, seg.Z=~x)
Estimated Break-Point(s):
psi1.x
 40.99

After that I need to allign both y1 and y2 to common x, for which I could use the difference in estimated beakpoints for each y, which is
> round(40.99-20.77)
[1] 20

and use this difference for aligning data

plot(x,y1)
points(x[-(1:(psi20)]-20,y2[-(1:20)], col=2)

But this seems to me rather complicated so I just asked if there is some shorter and less tedious option.

Actually I cannot decipher how your function could help me to plot y1 and y2 and starting to increase at the same point.

Cheers
Petr

> -----Original Message-----
> From: Jim Lemon <drjimlemon using gmail.com>
> Sent: Friday, August 3, 2018 12:32 AM
> To: PIKAL Petr <petr.pikal using precheza.cz>
> Cc: r-help mailing list <r-help using r-project.org>
> Subject: Re: [R] how to allign data
>
> Hi Petr,
> I recently had to align the minima of deceleration events to form an
> aggregate "braking profile" for different locations. It seems as
> though you are looking for something like:
>
> find_increase<-function(x,surround=10) {
>  inc_index<-which.max(diff(x))
>  indices<-(inc_index-surround):(inc_index+surround)
>  nneg<-sum(indices < 1)
>  # pad both ends with NA if needed
>  newx<-x[1:max(indices)]
>  if(nneg > 0) newx<-c(rep(NA,nneg),newx)
>  return(newx)
> }
>
> Jim
>
> On Thu, Aug 2, 2018 at 10:23 PM, PIKAL Petr <petr.pikal using precheza.cz> wrote:
> > Dear all
> >
> > Before I start to reinvent wheel I would like to ask you if you have some easy
> solution for aligning data
> >
> > I have something like this
> > x<-1:100
> > set.seed(42)
> > y1<-c(runif(20)+1, 1.2*x[1:80]+runif(80))
> > y2<-c(runif(40)+1, 1.2*x[1:60]+runif(60))
> >
> > plot(x,y1)
> > points(x,y2, col=2)
> >
> > with y increase starting at various x.
> >
> > I would like to allign data so that the increase starts at the same x point,
> something like
> >
> > plot(x,y1)
> > points(x[-(1:20)]-20,y2[-(1:20)], col=2)
> >
> > I consider using strucchange or segmented packages to find break(s) and
> "shift" x values according to this break. But maybe somebody already did
> similar task (aligning several vectors according to some common breakpoint)
> and could offer better or simpler solution.
> >
> > Best regards.
> > Petr
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Osobní údaje: Informace o zpracování a ochraně osobních údajů obchodních partnerů PRECHEZA a.s. jsou zveřejněny na: https://www.precheza.cz/zasady-ochrany-osobnich-udaju/ | Information about processing and protection of business partner’s personal data are available on website: https://www.precheza.cz/en/personal-data-protection-principles/
Důvěrnost: Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a podléhají tomuto právně závaznému prohláąení o vyloučení odpovědnosti: https://www.precheza.cz/01-dovetek/ | This email and any documents attached to it may be confidential and are subject to the legally binding disclaimer: https://www.precheza.cz/en/01-disclaimer/