Hi Stephanie Absolutely right! My CSV was imported as a factor. Reading the R FAQ:
http://cran.r-project.org/doc/FAQ/R-FAQ.html#How-do-I-convert-factors-to-numeric_003f I actually need to do: as.numeric(as.character(spectra.wavelength)) to get back to my original data. Many thanks for the pointer mike Stephanie Kovalchik wrote: > > Is spectra.wavelength a factor? If so, plot will treat it as > categorical and not draw a line. Try the following modification. > > plot(as.numeric(spectra.wavelength), cormat, type = "l", ylim=c(-1,1), > xlab="Wavelength (nm)", ylab="Correlation") > > Quoting MikSmith <[email protected]>: > >> >> Hi >> >> I'm trying to write a generic script for processing some data which >> finishes >> off with some plots. Given Im never sure how many columns will be in my >> dataframe I wanted to using the following >> >> plot(spectra.wavelength, cormat, type = "l", ylim=c(-1,1), >> xlab="Wavelength >> (nm)", ylab="Correlation") >> >> however even if I specify as type="l" it appears plot as points (right >> hand >> plot). If I specify a range such as >> >> plot(650:700, cormat, type = "l", ylim=c(-1,1), xlab="Wavelength (nm)", >> ylab="Correlation") >> >> it looks good (left hand plot). If I try something like: >> >> plot(spectra.wavelength[1]:spectra.wavelength[length(spectra.wavelength)], >> cormat, type = "l", ylim=c(-1,1), xlab="Wavelength (nm)", >> ylab="Correlation") >> >> it fails with "variable lengths differ" and when I look at >> spectra.wavelength[1] it gives me the value but then states there are 53 >> levels. >> >> What does this mean and how can I get the result I want??! >> >> many thanks >> >> mike http://www.nabble.com/file/p23562717/1.pdf 1.pdf >> -- >> View this message in context: >> http://www.nabble.com/Using-column-length-in-plot-gives-error-tp23562717p23562717.html >> Sent from the R help mailing list archive at Nabble.com. >> >> ______________________________________________ >> [email protected] 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. >> > > ______________________________________________ > [email protected] 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. > > -- View this message in context: http://www.nabble.com/Using-column-length-in-plot-gives-error-tp23562717p23582038.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [email protected] 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.
