Hi Greg,

Thanks,

I got the 1st example to work using the following code:


data <- read.csv("http://doylesdartden.com/Monthly-pH-example.csv", sep=",")

attach(data)

par(mfrow=c(2,1))
scatter.smooth( Year, MC.pH )
scatter.smooth( Year, MV.pH )


This is good but what I'm really looking for is to have them on the same
graph.


I tried your second example using the code below but got:

"Error in plot.window(...) : need finite 'ylim' values"

here is the code I used


data <- read.csv("http://doylesdartden.com/Monthly-pH-example.csv", sep=",")

attach(data)


plot( Year, MC.pH, ylim=range(MC.pH,MV.pH) , col='blue')

points( Year, MV.pH, col='green' )

lines( loess.smooth(Year,MC.pH), col='blue')

lines( loess.smooth(Year,MV.pH), col='green')


Thanks again

David


On Tue, Apr 24, 2012 at 1:45 PM, Greg Snow <538280@gmail.com> wrote:

> Assuming that you want event as the x-axis (horizontal) you can do
> something like (untested without reproducible data):
>
> par(mfrow=c(2,1))
> scatter.smooth( event, pH1 )
> scatter.smooth( event, pH2 )
>
> or
>
> plot( event, pH1, ylim=range(pH1,pH2) , col='blue')
> points( event, pH2, col='green' )
> lines( loess.smooth(event,pH1), col='blue')
> lines( loess.smooth(event,pH2), col='green')
>
> Only do the second one if pH1 and pH2 are measured on the same scale
> in a way that the comparison and any crossings are meaningful or if
> there is enough separation (but not too much) that there is no
> overlap, but still enough detail.
>
>
>
> On Mon, Apr 23, 2012 at 10:40 PM, R. Michael Weylandt
> <michael.weylandt@gmail.com> wrote:
> > The scatter plot is easy:
> >
> > plot(pH1 ~ pH2, data = OBJ)
> >
> > When you say a loess for each -- how do you break them up? Are there
> > repeat values for pH1? If so, this might be hard to do in base
> > graphics, but ggplot2 would make it easy:
> >
> > library(ggplot2)
> > ggplot(OBJ, aes(x = pH1, y = pH2)) + geom_point() + stat_smooth() +
> > facet_wrap(~factor(pH1))
> >
> > or something similar.
> >
> > Michael
> >
> > On Mon, Apr 23, 2012 at 11:26 PM, David Doyle <kydaviddoyle@gmail.com>
> wrote:
> >> Hi folks.
> >>
> >> If I have the following in my "data"
> >>
> >> event    pH1    pH2
> >> 1            4.0     6.0
> >> 2            4.3     5.9
> >> 3            4.1     6.1
> >> 4            4.0     5.9
> >> and on and on..... for about 400 events
> >>
> >> Is there a way I can get R to plot event vs. pH1  and event vs. pH2 and
> >> then do a loess or lowess line for each??
> >>
> >> Thanks in advance
> >> David
> >>
> >>        [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-help@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.
> >
> > ______________________________________________
> > R-help@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.
>
>
>
> --
> Gregory (Greg) L. Snow Ph.D.
> 538280@gmail.com
>

	[[alternative HTML version deleted]]

