Using column length in plot gives error
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 <mike at hsm.org.uk>:
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.
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