[Fwd: Re: Fw: [R] Contour plot]

[Petr Pikal]

On 9 Feb 2005 at 16:32, dhkblaszyk at zeelandnet.nl wrote:

> Petr,
> 
> It works perfectly! But I still have a question;
> 
> I have fit the following data;
> 
> x,y,z
> 1,10,11
> 2,11,15
> 3,12,21
> 4,13,29
> 5,14,39
> 6,15,51
> 7,16,65
> 8,17,81
> 9,18,99
> 10,19,119
> 
> >dat.lm <- lm(z~I(x^2)+y, data=dat)
> >dat.lm
> 
> Call:
> lm(formula = z ~ I(x^2) + y, data = dat)
> 
> Coefficients:
> (Intercept)       I(x^2)            y
>   1.841e-14    1.000e+00    1.000e+00
> 
> How do I create the "z" matrix from dat.lm?? Without having to type
> over all the coefficients?

Maybe
expand.grid() and predict()

# new data
x<-1:10
y<-20:60

new.df<-expand.grid(x,y) #make data.frame
names(new.df)<-c("x","y") #change to propper names

contour(x,y,matrix(predict(dat.lm, new.df),10,41))

Cheers
Petr



> 
> Kind regards, Darius Blaszijk
> 
> ------------------------- Oorspronkelijk bericht
> ------------------------- Onderwerp: Re: Fw: [R] Contour plot Van:    
>   "Petr Pikal" <petr.pikal at precheza.cz> Datum:     Wo, 9 februari,
> 2005 11:23 am Aan:       dhkblaszyk at zeelandnet.nl
>            r-help at stat.math.ethz.ch
> ----------------------------------------------------------------------
> ----
> 
> Hi Darius
> 
> 
> On 8 Feb 2005 at 17:43, dhkblaszyk at zeelandnet.nl wrote:
> 
> > I understand that I need to have a (in this case) square matrix with
> > all
> the data. But the question now is;
> >
> > - can the contourplot not interpolate the missing values
> >
> > or alternatively
> >
> > - I have fit a model to the z data (z = 100 + 0.5x + 0.5y). How can
> > I
> make from this model a "square" matrix z to make a contour plot?
> 
> 
> Will
> 
> x<-1:10
> y<-1:10
> z <- outer(x,y,function(x,y) 100 + 0.5*x + 0.5*y)
> contour(x,y,z)
> 
> work as you wish?
> Cheers
> Petr
> 
> 
> >
> > Kind regards, Darius Blaszijk
> >
> > ----- Original Message -----
> > From: "Achim Zeileis" <Achim.Zeileis at wu-wien.ac.at>
> > To: <dhkblaszyk at zeelandnet.nl>
> > Cc: <r-help at stat.math.ethz.ch>
> > Sent: Tuesday, February 08, 2005 1:51 AM
> > Subject: Re: [R] Contour plot
> >
> >
> > > On Tue, 8 Feb 2005 01:15:06 +0100 dhkblaszyk at zeelandnet.nl wrote:
> > >
> > > > Hello,
> > > >
> > > > I would like to make a contourplot of the following data;
> > > >
> > > > > x <- 1:10
> > > > > y <- 1:10
> > > > > z <- 100:110
> > > >
> > > > By doing >contour(x,y,z) I get the following error;
> > > >
> > > > "Error in contour.default(x, y, z) : no proper `z' matrix
> > > > specified"
> > > >
> > > > How do I fix this??
> > >
> > > x and y specify a grid and thus z must provide a value for each
> combination of the x's and y's! For example:
> > >   x <- y <- 1:10
> > >   contour(x, y, outer(x, y))
> > > Also look at
> > >   outer(x, y)
> > > and read ?contour.
> > >
> > > Z
> > >
> > > > Kind regards, Datius Blaszijk
> > > >
> > > > [[alternative HTML version deleted]]
> > > >
> > > > ______________________________________________
> > > > R-help at stat.math.ethz.ch mailing list
> > > > https://stat.ethz.ch/mailman/listinfo/r-help
> > > > PLEASE do read the posting guide!
> > > > http://www.R-project.org/posting-guide.html
> > > >
> >
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide!
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> 
> Petr Pikal
> petr.pikal at precheza.cz
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide!
> http://www.R-project.org/posting-guide.html

Petr Pikal
petr.pikal at precheza.cz