Displaying 7 results from an estimated 7 matches for "geochemists".
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geochemist
2003 Jul 15
2
R, geochemistry, ternary diagrams
...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?
2008 Sep 21
2
Variable Selection for data reduction and discriminant anlaysis
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
2012 Feb 15
7
matching a sequence in a vector?
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 <-
2003 Mar 25
2
Re: Bar plot with variable width (down a drill hole) - now missing intervals?
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 =
2001 Jun 25
1
Linking R to GIS
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
2011 Oct 13
3
nls: singular convergeance
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
2008 Sep 22
1
R-help Digest, Vol 67, Issue 23
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