[R] Q - scatterplot, plot function & trellis linear regressions???

[Simon Knapp]

I presume you mean car::scatterplot

A1) plot is a generic function for plotting 'things' and scatterplot
is a specific tool provided by that library

A2) from the documentation one infers that
      1) the straight line is a regression line
      2) the other lines are produced using loess
           a) the solid line is fitted to the data
           b) the dotted lines are created by: "a smoother is applied
to the root-mean-square positive and negative residuals from the loess
line to display conditional spread and asymmetry"

A3) you forgot the data argument (at least).

Cheers,
Simon

On Sat, May 19, 2012 at 11:34 AM, Jhope <jeanwaijang at gmail.com> wrote:
> Hi R-listers,
>
> Q1) What is the difference between the scatterplot and plot function?
>
> Q2) I am able to make a graph with the scatterplot function:
>
> scatterplot(DevelopIndex ~ Veg,
> +             data = Turtle,
> +             xlab = "Vegetation border (m)",
> +             ylab = "Embryonic development index")
>
> And have been successful. But I do not know if the lines are for: linear,
> non-linear, mean, upper and lower limits or percentile? This shows side
> boxplots and 4 lines.
>
> Yet this plot only has one regression line and no side boxplots?:
>
> EDIHTL <- lm(DevelopIndex~ HTL, data=Turtle)
>> plot(DevelopIndex~HTL, data=Turtle, pch=16,
>       xlab="High tide line (m)", ylab="Embryonic development index")
>> abline(EDIHTL)
>
> Q-3
> I am trying to make a trellis of linear regressions. I want 3 windows
> displaying 3 events of linear regression (two-way interactions). I have been
> trying this:
>
> require(lattice)
>> library(lattice)
>> trellis.par.set(col.whitebg())
>> scatterplot(DevelopIndex~Veg|Aeventexhumed,
> +             xlab = "Vegetation border",
> +             ylab = "Embryonic development index")
> Error in eval(expr, envir, enclos) : object 'DevelopIndex' not found
>
>  Please advise, many thanks.
> Jean
>
> --
> View this message in context: http://r.789695.n4.nabble.com/Q-scatterplot-plot-function-trellis-linear-regressions-tp4630562.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.