Hi all, I am new to R and I have got a question in regards to factors. Say I have a simple dataset like the following: Name Time Value a 1:00 1.25 a 2:00 1.26 b 1:00 1.29 b 2:00 1.28 c 1:00 1.21 c 1:30 1.20 c 2:00 1.23 I want to write a script that automatically plot value against time for a, b and c. Because I have got more than 1 datasets, therefore the name of the next dataset may consist d, e, h and g. So I will need a script that can detect the changes in Name automatically. Thank you very much for your time. Chris -- View this message in context: http://www.nabble.com/Question-about-Factors-tp25428665p25428665.html Sent from the R help mailing list archive at Nabble.com.
Chris Li wrote:> > Hi all, > > I am new to R and I have got a question in regards to factors. > > Say I have a simple dataset like the following: > > Name Time Value > a 1:00 1.25 > a 2:00 1.26 > b 1:00 1.29 > b 2:00 1.28 > c 1:00 1.21 > c 1:30 1.20 > c 2:00 1.23 > > I want to write a script that automatically plot value against time for a, > b and c. Because I have got more than 1 datasets, therefore the name of > the next dataset may consist d, e, h and g. So I will need a script that > can detect the changes in Name automatically. > > Thank you very much for your time. > > Chris >I'm assuming you want something like a separate scatter plot for each "level" of Name-- i.e. for this example a plot of Value ~ Time for 'a', then a new plot of Value ~ Time for 'b', ect. One easy way to chop a data frame into a bunch of mini data frames based on the value of a factor is the by() function. For example, supposing your data frame is named "data", the following might produce what you want: by( data, data[[ 'Name' ]], function(slice){ # Slice is now a smaller data frame which contains only the # values which share a row with a one of the factor levels in Name dev.new() plot( Value ~ Time, data = slice, main = paste('Scatter plot for', slice[[ 'Name' ]][1]) ) }) Another way to easily create the same plots and visualize them all on one page as a series of small multiples would be to use Hadley Wickham's ggplot2 package: qplot( Value ~ Time, data = data ) + facet_wrap( ~ Name ) Hope some of this helps! -Charlie ----- Charlie Sharpsteen Undergraduate Environmental Resources Engineering Humboldt State University -- View this message in context: http://www.nabble.com/Question-about-Factors-tp25428665p25429985.html Sent from the R help mailing list archive at Nabble.com.
On Mon, Sep 14, 2009 at 5:19 AM, Schalk Heunis <schalk.heunis@enerweb.co.za>wrote:> Chris > try this (assume your dataset is in a dataframe called ms): > library(lattice) > xyplot(Value~Time|Name,data = ms) > > HTH > Schalk > > > > On Mon, Sep 14, 2009 at 2:19 AM, Chris Li <chrisli@austwaterenv.com.au>wrote: > >> >> Hi all, >> >> I am new to R and I have got a question in regards to factors. >> >> Say I have a simple dataset like the following: >> >> Name Time Value >> a 1:00 1.25 >> a 2:00 1.26 >> b 1:00 1.29 >> b 2:00 1.28 >> c 1:00 1.21 >> c 1:30 1.20 >> c 2:00 1.23 >> >> I want to write a script that automatically plot value against time for a, >> b >> and c. Because I have got more than 1 datasets, therefore the name of the >> next dataset may consist d, e, h and g. So I will need a script that can >> detect the changes in Name automatically. >> >> Thank you very much for your time. >> >> Chris >> -- >> View this message in context: >> http://www.nabble.com/Question-about-Factors-tp25428665p25428665.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> 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. >> > >[[alternative HTML version deleted]]
The suggestions from others to use lattice's xyplot, or ggplot2 are good.
If you want an explicit loop you can do something like:
for ( nm in unique(mydat$Name) ) {
with( subset( mydf, Name==nm) ,
{
plot(Time, Value, title=nm)
readline('CR to continue ')
}
)
}
At 5:19 PM -0700 9/13/09, Chris Li wrote:>Hi all,
>
>I am new to R and I have got a question in regards to factors.
>
>Say I have a simple dataset like the following:
>
>Name Time Value
>a 1:00 1.25
>a 2:00 1.26
>b 1:00 1.29
>b 2:00 1.28
>c 1:00 1.21
>c 1:30 1.20
>c 2:00 1.23
>
>I want to write a script that automatically plot value against time for a, b
>and c. Because I have got more than 1 datasets, therefore the name of the
>next dataset may consist d, e, h and g. So I will need a script that can
>detect the changes in Name automatically.
>
>Thank you very much for your time.
>
>Chris
>--
>View this message in context:
>http://*www.*nabble.com/Question-about-Factors-tp25428665p25428665.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.
--
--------------------------------------
Don MacQueen
Environmental Protection Department
Lawrence Livermore National Laboratory
Livermore, CA, USA
925-423-1062