search for: geochemists

...agrams, and if so, it looks as though it should be doable in R, but I don't know enough about the lower levels of R graphics to do it myself (yet). Looking at his speed and volume requirements, R can handle them easily, even on a machine about 1/4 of the speed he has in mind. Are there enough geochemists using R already that he'd find like-minded people to discuss technical issues with if he _did_ switch to R? Is there a package somewhere already that does ternary and other geochemistry diagrams?

Hello all, I'm dealing with geochemical analyses of some rocks. If I use the full composition (31 elements or variables), I can get reasonable separation of my 6 sources. Then when I go onto do LDA with the 6 groups, I get excellent separation. I feel like I should be reducing the variables to thos that are providing the most discrimination between the groups as this is important

Hi All, I've been trawling through the documentation and listserv archives on this topic -- but as yet have not found a solution. I'm sure this is pretty simple with R, but I cannot work out how without resorting to ugly nested loops. As far as I can tell, grep, match, and %in% are not the correct tools. Question: given these vectors -- patrn <- c(1,2,3,4) exmpl <-

Hi again, Thanks Ted and Marc its works. But of course after pulling in in some real life data I discoverd one hitch. Often there are missing intervals. For example: from <- c(0, 1.2, 4.0, 4.2, 5.0, 25.0, 30.1, 45) to <- c(1.2, 4.0, 4.2, 5.0, 25, 30.1, 36.2, 50) intensity <- c(0, 1, 3, 2, 1, 0, 2, 5) barplot(intensity, width = -(to - from), space = 0, horiz = TRUE, ylim =

Dear All, Has anyone worked with linking R to both ArcView and MapInfo GIS systems? My desire is to capture object selection from GIS and pass to R and to return spatially based statistical model results from R to GIS. If both could simultaneously access the same data file this would be a bonus. My inclination is to put together some routines based on ODBC linking but thought I would seek like

Dear R-experts, I have 28 data points that I would like to fit with a non linear broken-stick -- with three fitted parameters. When I view trace -- and use the final values as lines on the graph of data -- it looks pretty good. Q1. Why am I getting singular convergeance? Q2. Can you suggest another approach that may prove more satisfying? I have read previous examples on nls and this sort of

Warranty on Accuracy, Precision, Legality, ... of R in Research (These questions may well have been raised.) What is the implied warranty of using R for research & publications, consulting, etc.? Alternately, how does one obtain such a warranty? Your answers will be much appreciated. Perhaps you can point me to some websites which discussed this subject in the past. Thanks & regards