similar to: Use of geometric mean for geochemical concentrations

Displaying 20 results from an estimated 1100 matches similar to: "Use of geometric mean for geochemical concentrations"

2024 Jan 22
3
Use of geometric mean for geochemical concentrations
A statistical question, not specific to R. I'm asking for a pointer for a source of definitive descriptions of what types of data are best summarized by the arithmetic, geometric, and harmonic means. As an aquatic ecologist I see regulators apply the geometric mean to geochemical concentrations rather than using the arithmetic mean. I want to know whether the geometric mean of a set of
2024 Jan 24
1
Use of geometric mean for geochemical concentrations [RESOLVED]
On Mon, 22 Jan 2024, Rich Shepard wrote: > As an aquatic ecologist I see regulators apply the geometric mean to > geochemical concentrations rather than using the arithmetic mean. I want to > know whether the geometric mean of a set of chemical concentrations (e.g., > in mg/L) is an appropriate representation of the expected value. If not, I > want to explain this to non-technical
2024 Jan 22
1
Use of geometric mean for geochemical concentrations
better posted on r-sig-ecology? -- or maybe even stack exchange? Cheers, Bert On Mon, Jan 22, 2024 at 7:45?AM Rich Shepard <rshepard at appl-ecosys.com> wrote: > A statistical question, not specific to R. > > I'm asking for a pointer for a source of definitive descriptions of what > types of data are best summarized by the arithmetic, geometric, and > harmonic >
2024 Jan 22
1
Use of geometric mean for geochemical concentrations
On Mon, 22 Jan 2024, Bert Gunter wrote: > better posted on r-sig-ecology? -- or maybe even stack exchange? Bert, Okay. Regards, Rich
2024 Jan 22
1
Use of geometric mean for geochemical concentrations
I think https://stats.stackexchange.com would be best: r-sig-ecology is pretty quiet these days On 2024-01-22 11:05 a.m., Rich Shepard wrote: > On Mon, 22 Jan 2024, Bert Gunter wrote: > >> better posted on r-sig-ecology? -- or maybe even stack exchange? > > Bert, > > Okay. > > Regards, > > Rich > > ______________________________________________
2024 Jan 22
1
Use of geometric mean .. in good data analysis
On Mon, 22 Jan 2024, Martin Maechler wrote: > I think it is a good question, not really only about geo-chemistry, but > about statistics in applied sciences (and engineering for that matter). > John W Tukey (and several other of the grands of the time) had the log > transform among the "First aid transformations": > > If the data for a continuous variable must all be
2024 Jan 22
2
Use of geometric mean .. in good data analysis
>>>>> Rich Shepard >>>>> on Mon, 22 Jan 2024 07:45:31 -0800 (PST) writes: > A statistical question, not specific to R. I'm asking for > a pointer for a source of definitive descriptions of what > types of data are best summarized by the arithmetic, > geometric, and harmonic means. In spite of off-topic: I think it is a good
2024 Jan 22
2
Use of geometric mean .. in good data analysis
Ah.... LOD's, typically LLOD's ("lower limits of detection"). Disclaimer: I am *NOT* in any sense an expert on such matters. What follows are just some comments based on my personal experience. Please filter accordingly. Also, while I kept it on list as Martin suggested it might be useful to do so, most folks probably can safely ignore the rant that follows as off topic and not
2024 Jan 22
1
Use of geometric mean .. in good data analysis
Still OT... but here is my own (I think previously mentioned here) rant on people thrashing about with log transformation and an all-too-common kludge to deal with zeros mixed among small numbers... https://gist.github.com/jdnewmil/99301a88de702ad2fcbaef33326b08b4 OP perhaps posting a link here to your question posed wherever you end up with it will help shorten this thread. On January 22, 2024
2011 Nov 21
1
Lattice graph help
Hi all I hope you might help me with some aspects of producing a graph in lattice. There are three things I have struggling with and that is: 1. to separate the horizontal box rows from each other; 2. to change the colour of the horizontal and vertical strips to white; and 3. to place the axes labels on the left y axes and on the bottom x axes. I would really appreciate some help. I have put the
2023 Mar 08
1
Default Generic function for: args(name, default = TRUE)
?.S3methods f <- function()(2) > length(.S3methods(f)) [1] 0 > length(.S3methods(print)) [1] 206 There may be better ways, but this is what came to my mind. -- Bert On Wed, Mar 8, 2023 at 11:09?AM Leonard Mada via R-help < r-help at r-project.org> wrote: > Dear R-Users, > > I want to change the args() function to return by default the arguments > of the default
2011 Nov 22
0
Lattice graph strips and axes
Hi all I was wondering if it is possible to get rid of the horizontal strips and produce each barchart with a left y axes and lower x axes only. Also can you specify an exact size of graph ie 88mm wide with a font size of 'x'. library(lattice) library(latticeExtra) n=as.factor(c(1:5,1:5))
2023 Mar 08
1
Default Generic function for: args(name, default = TRUE)
Dear R-Users, I want to change the args() function to return by default the arguments of the default generic function: args = function(name, default = TRUE) { ?? ?# TODO: && is.function.generic(); ?? ?if(default) { ?? ???? fn = match.call()[[2]]; ?? ???? fn = paste0(as.character(fn), ".default"); ?? ???? name = fn; ?? ?} ?? ?.Internal(args(name)); } Is there a nice way
2024 Feb 24
1
Clustering Functions used by Reverse-Dependencies
Dear R Users, Are there any tools to extract the function names called by reverse-dependencies? I would like to group these functions using clustering methods based on the co-occurrence in the reverse-dependencies. Utility: It may be possible to split complex packages into modules with fewer reverse-dependencies. Package pkgdepR may offer some of the functionality; but I did not have time to
2008 Dec 09
1
creating standard curves for ELISA analysis
Hello R guru's I am a newbie to R, In my research work I usually generate a lot of ELISA data in form of absorbance values. I ususally use Excel to calculate the concentrations of unknown, but it is too tedious and manual especially when I have 100's of files to process. I would appreciate some help in creating a R script to do this with minimal manual input. s A1-G1 and A2-G2 are
2023 Oct 16
1
Create new data frame with conditional sums
If one makes the reasonable assumption that Pct is much larger than Cutoff, sorting Cutoff is the expensive part e.g O(nlog2(n) for Quicksort (n = length Cutoff). I believe looping is O(n^2). Jeff's approach using findInterval may be faster. Of course implementation details matter. -- Bert On Mon, Oct 16, 2023 at 4:41?AM Leonard Mada <leo.mada at syonic.eu> wrote: > > Dear
2023 Oct 16
1
Create new data frame with conditional sums
Dear Jason, The code could look something like: dummyData = data.frame(Tract=seq(1, 10, by=1), ?? ?Pct = c(0.05,0.03,0.01,0.12,0.21,0.04,0.07,0.09,0.06,0.03), ?? ?Totpop = c(4000,3500,4500,4100,3900,4250,5100,4700,4950,4800)) # Define the cutoffs # - allow for duplicate entries; by = 0.03; # by = 0.01; cutoffs <- seq(0, 0.20, by = by) # Create a new column with cutoffs dummyData$Cutoff
2014 Nov 13
1
metafor - code for analysing geometric means
?Dear All I have some data expressed in geometric means and 95% confidence intervals. Can I code them in metafor as: rma(m1i=geometric mean 1, m2i=geometric mean 2, sd1i=geometric mean 1 CI /3.92, sd2i=geometric mean 2 CI/3.92.......etc, measure="MD") All of the studies use geometric means. Thanks! Edward ---------------------------- [[alternative HTML version deleted]]
2005 Jan 04
1
quantiles for geometric distribution
Dear list, I have got an array with observational values t and I would like to fit a geometric distribution to it. As I understand the geometric distribution, there is only one parameter, the probability p. I estimated it by 1/mean(t). Now I plotted the estimated density function by plot(ecdf(t),do.points=FALSE,col.h="blue"); and I would like to add the geometric distribution. This
2008 Mar 16
1
R code for the MLE of a geometric distribution
Does anyone know how to approach R code for the MLE of a geom. distribution? thanks! [[alternative HTML version deleted]]