Displaying 20 results from an estimated 5000 matches similar to: "Setting Number of Displayed Digits"
2024 Jan 30
2
Use of geometric mean for geochemical concentrations
Dear Rich,
It depends how the data is generated.
Although I am not an expert in ecology, I can explain it based on a biomedical example.
Certain variables are generated geometrically (exponentially), e.g. MIC or Titer.
MIC = Minimum Inhibitory Concentration for bacterial resistance
Titer = dilution which still has an effect, e.g. serially diluting blood samples;
Obviously, diluting the
2012 Aug 07
3
reshape2's dcast() Adds NAs to Data Frame
I need to understand how and why dcast() adds NAs to a data frame that
contained no missing values.
The database table of chemical concentrations has all missing values
removed because they cannot contribute to data analyses. The structure of
the R data frame of these data have no NA values, and neither does the data
frame resulting from applying the reshape2 melt() function to it. However,
2013 Mar 14
2
NADA and cenmle
Hi,
I am using the cenmle function from the NADA package and some of my data
are negative values. As a result the cenmle function will not work and
NaN's are produced. I try to change the distribution to Gaussian, but it
still will not run.
Could somebody please help me with this?
Thanks
--
Shane
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2011 Sep 22
3
Bivariate Scatter Plots with Lattice
Data frame has this structure:
'data.frame': 11169 obs. of 4 variables:
$ stream : Factor w/ 37 levels "Burns","CIL",..: 1 1 1 1 1 1 1 1 1 1 ...
$ sampdate: Date, format: "1987-07-23" "1987-09-17" ...
$ param : Factor w/ 8 levels "As","Ca","Cl",..: 1 1 1 1 1 1 1 1 1 1 ...
$ quant : num 0.01 0.01 0.01 0.01
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
2011 Sep 02
2
Chemical Names in Data Frames
Greetings -
I am working on some data that contain chemical names with air concentrations, and I am creating a data frame with date/time and each chemical having its own column. However, these are organic chemicals (e.g. 1-butene, 2,3,4-trimethylbenzene etc). The package I am going to be using the data with is openair, and many of the great functions require you to specify a column name which
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
2011 Nov 02
2
Proper Syntax for Logical Subset in Subset()
I have measured values for 47 chemicals in a stream. After processing
the original data frame through reshape2, the recast data frame has this
structure:
'data.frame': 256 obs. of 47 variables:
$ site : Factor w/ 143 levels "BC-0.5","BC-1",..: 1 1 1 2 2 2 2 2 2 2
...
$ sampdate : Date, format: "1996-04-19" "1996-05-21" ...
$ Acid :
2006 Mar 23
1
PCA, Source analysis and Unmixing, environmental forensics
I am using R for environmental forensics (determination of the sources
and/or groupings in mixtures of organic chemicals in the field). The
goal is to determine in there are groups of samples with
similar/dissimilar compositions, and to assign samples to a potential
source or a mixture of sources based on the composition (unmixing and
source allocation). Typically there are 10 to 50 chemicals that
2017 Sep 01
4
Sync mailservera!
Hello to all !
I have two servers using dovecot and want to sync them with doveasm ......
I am using usersb as user backend ....database
Can anyone help me config them... Is there any use guide about it ?
Thans in advance for the help !
Nick
2005 Jun 22
4
tc on a PDA
hello,
i have a 5500 iPaq with familiar 0.8.2 on it and i don''t know how to
install a traffic shaper tool on it.
I installed iproute2 package i found on familiar site and for that i
have the tc and ip commands, but when trying to add a qdisc, as a
dummy example, i get the next answer:
> tc qdisc add dev wlan0 root cbq bandwidth 100Mbit avpkt 100
RTNETLINK answers: Invalid argument
2010 May 04
2
Package Rsafd
Dear R community,
I am looking for the package "Rsafd". It is not listed on the CRAN directory. I am wondering anyone has idea with this package. Thans a lot!
Bo
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2009 Oct 16
2
Different way of scaling data
Hi,
I have a data.frame that I need to scale.
I've been using the scale function and it works nicely.
Some of the libraries I'm testing won't accept negative values for data,
so I need to find a way to scale the data from 0 to 1
Any ideas?
Thans!
2009 May 27
2
How to set a filter during reading tables
We are reading big tables, such as,
Chemicals <-
read.table('ftp://ftp.bls.gov/pub/time.series/wp/wp.data.7.Chemicals',header
= TRUE, sep = '\t', as.is =T)
I was wondering if it is possible to set a filter during loading so that
we just load what we want not the whole table each time. Thanks,
-james
2010 Oct 15
2
Time vs Concentration Graphs by ID
Hello-- I have a data for small population who took 1 drug at 3 different
doses. I have the actual drug concentrations as well as predicted
concentrations by my model. This is what I'm looking for:
- Time vs Concentration by ID (individual plots), with each subject
occupying 1 plot -- there is to be 9 plots per page (3x3)
- Observed drug concentration is made up of points, and predicted drug
2006 Feb 17
3
dansguardian+squid masquerading not working
Hello Everyone!
I am using shorewall-3.0.5 on suse linux.
Recently we have implemented dansguardian running on 8080 and squid on
port 3128.
Previously (before dans guardian) masquerading was working fine but
after the implementation of dansguardian masquerading is not working.
My rules file has entry
Previous entry was
ACCEPT loc:192.192.192.3 net
REDIRECT loc 8080 tcp
2005 Apr 19
3
Help with predict.lm
Hi
I have measured the UV absorbance (abs) of 10 solutions of a substance at
known concentrations (conc) and have used a linear model to plot a
calibration graph with confidence limits. I now want to predict the
concentration of solutions with UV absorbance results given in the new.abs
data.frame, however predict.lm only appears to work for new "conc" variables
not new "abs"
2012 Jan 26
1
Scaling Memory at WIndows
Hello.
I am using XEN 3.4.2 and 4.0.1 with dom0 based on Centos 5.x and Debian 6.0.
I can scale RAM with paravirt domU''s by using xm mem-max and xm mem-set
But, I see this: http://msdn.microsoft.com/en-us/windows/hardware/gg487553 .
Is it possible to change memory at Window HVM domU''s without reboot?
Thans a lot!
--
Best Regards,
alex.faq8@gmail.com
2012 Apr 29
1
virtio drivers for Centos 5.8
Hi,
So I updated my guest from 5.1 to 5.8 via a complete yum update, many many packages BTW.
I shutdown the guest, change its "Disk bus" from IDE to Virtio and then upon boot, I get kernel panics as no disk can be found. I do get the splash screen at first however.
My guest has /dev/hda, should I change its fstab to reflect /dev/vda instead?
Thans in advance,
- aurf
2004 Nov 22
1
Left justification af dimnames in tables.
Hi helpeRs.
When I do two-ways tables dimnames in columns are almost left-adjusted:
<- factor(rbinom(30,1,.3),labels=c("first","second"))
> b <- a
> table(a,b)
b
a first second
first 21 0
second 0 9
If I do a oneway table however, dimnames are right-adjusted:
table(a)
a
first second
21 9
Actually I must admit I