[R] Depth vs Temp graph for different transects

[Ben Tupper]

On Sep 1, 2014, at 12:32 PM, David Winsemius <dwinsemius at comcast.net> wrote:

> 
> On Sep 1, 2014, at 3:52 AM, Tinus Sonnekus wrote:
> 
>> Hi All,
>> 
>> Have the following code. The graph works well plotting the 15 transect for
>> me however the legend shows a total of 22 transects. The original data has
>> 22 transects numbered from 1 to 22. New data set got only 15. How can I get
>> the legend to show only the transects plotted.
>> 
>> 
>> # Create Line Chart
>> 
>> 
>> TAll <- read.csv("TAll Data.csv")
> 
> You have set up a situation where we can only guess.


If this data is generated by a CTD or similar instrument then I highly recommend you use Dan Kelley's oce package.  It will help you manage, analyze and display the cast data.

http://cran.r-project.org/web/packages/oce/index.html

Cheers,
Ben


> 
>> 
>> 
>> # convert factor to numeric for convenience
>> TAll$Tran <- as.numeric(TAll$Trans)
>> nTrans <- max(TAll$Trans)
>> 
>> # get the range for the x and y axis
>> xrange <- range(TAll$Temp)
>> yrange <- range(TAll$Depth)
>> 
>> # set up the plot
>> plot(xrange, yrange, ylim = rev(yrange), type="n", xlab="Temp (deg C)",
>> ylab="Depth (m)" )
>> colors <- rainbow(nTrans)
>> linetype <- c(1:nTrans)
>> plotchar <- seq(1,1+nTrans,1)
>> 
>> # add lines
>> for (i in 1:nTrans) {
>> tree <- subset(TAll, Trans==i)
>> lines(tree$Temp, tree$Depth, type="b", lwd=1.5,
>>   lty=linetype[i], col=colors[i], pch=plotchar[i])
>> }
>> 
>> # add a legend
>> legend(xrange[-2], yrange[-2], 1:nTrans, cex=0.8, col=colors,
>> pch=plotchar, lty=linetype, title="Transect")
>> 
> If nTrans is 22 then you are getting what you ask for. If you subsetted a dataset where TAll$Trans was a factor then it's perfecty possible that the legend would have more items than the subset. Perhaps you should use `length` or length(unique(.))` rather than `max`.
> 
> -- 
> David.
> 
> 
>> 
>> 
>> Thanks for the help,
>> Tinus
>> 
>> -- 
>> M.J. Sonnekus
>> PhD Candidate (The Phytoplankton of the southern Agulhas Current Large
>> Marine Ecosystem (ACLME))
>> Department of Botany
>> South Campus
>> Nelson Mandela Metropolitan University
>> PO Box 77000
>> Port Elizabeth
>> South Africa
>> 6031
>> 
>> Cell: 082 080 9638
>> E-mail: tsonnekus at gmail.com
>> 
>> 	[[alternative HTML version deleted]]
>> 
>> ______________________________________________
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> 
> David Winsemius, MD
> Alameda, CA, USA
> 
> ______________________________________________
> 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.