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
2024 Sep 05
3
BUG: atan(1i) / 5 = NaN+Infi ?
On 2024-09-05 4:23 p.m., Leo Mada via R-help wrote:
> Dear R Users,
>
> Is this desired behaviour?
> I presume it's a bug.
>
> atan(1i)
> # 0+Infi
>
> tan(atan(1i))
> # 0+1i
>
> atan(1i) / 5
> # NaN+Infi
There's no need to involve atan() and tan() in this:
> (0+Inf*1i)/5
[1] NaN+Infi
Why do you think this is a bug?
Duncan Murdoch
2024 Sep 05
2
BUG: atan(1i) / 5 = NaN+Infi ?
atan(1i) -> 0 + Inf i
complex(1/5) -> 0.2 + 0i
atan(1i) -> (0 + Inf i) * (0.2 + 0i)
-> 0*0.2 + 0*0i + Inf i * 0.2 + Inf i * 0i
infinity times zero is undefined
-> 0 + 0i + Inf i + NaN * i^2
-> 0 + 0i + Inf i - NaN
-> NaN + Inf i
I am not sure how complex arithmetic could arrive at another answer.
I advise against messing with infinities... use atan2() if you don't
2024 Sep 05
1
BUG: atan(1i) / 5 = NaN+Infi ?
Dear Bert,
These behave like real divisions/multiplications:
complex(re=Inf, im = Inf) * 5
# Inf+Infi
complex(re=-Inf, im = Inf) * 5
# -Inf+Infi
The real division / multiplication should be faster and also is well behaved. I was expecting R to do the real division/multiplication on a complex number. Which R actually does for these very particular cases; but not when only Im(x) is Inf.
2024 Sep 05
1
BUG: atan(1i) / 5 = NaN+Infi ?
> complex(real = 0, imaginary = Inf)
[1] 0+Infi
> Inf*1i
[1] NaN+Infi
>> complex(real = 0, imaginary = Inf)/5
[1] NaN+Infi
See the Note in ?complex for the explanation, I think. Duncan can correct
if I'm wrong.
-- Bert
On Thu, Sep 5, 2024 at 3:20?PM Leo Mada <leo.mada at syonic.eu> wrote:
> Dear Bert,
>
> These behave like real divisions/multiplications:
>
2024 Jun 02
1
Tools to modify highlighted areas in pdf documents?
? Sat, 1 Jun 2024 16:16:23 +0000
Leo Mada via R-help <r-help at r-project.org> ?????:
> When highlighting pdf-documents with Microsoft Edge, the bounding box
> is sometimes misplaced, and quite ugly so. It also lacks the ability
> to draw lines or arrows.
>
> On the other hand, I did not get used to Acrobat Reader: it usually
> involves much more effort to add specific