Displaying 20 results from an estimated 30000 matches similar to: "stably updating the SD"
2004 May 21
2
bars with sd
I need some help for a curious question of a friend of mine.
She usually does some experiments (3-5 repeats for each exp) and then she
calculates mean and standard deviation.
In microsoft excel she writes something like the following
sample mean sd
a 1.25 0.35
b 2.65 0.65
c 3.45 0.50
She can do a vertical barplot graph just giving mean value and specifying
the
2019 Feb 19
3
Documentation for sd (stats) + suggestion
I cannot file suggestions on bugzilla, so writing here.
As far as I can tell, the manual help page for ``sd``
?sd
does not explicitly mention that the formula for the standard deviation is
the so-called "Bessel-corrected" formula (divide by n-1 rather than n).
I suggest it should be stated near the top.
I would also suggest (feature request!) that either
- a population standard
2001 Jun 04
0
question on bootstrapping mean and sd
Not so much an R question, as a methodology one...
Dealing with some reviewers comments, one of the reviewers suggests
bootstrapping my group means and standard deviations since 2 of my 3 groups
have a small sample size. My data is geochemical data, and a variety of
clustering methods finds 3 groups in the data. One group has 50 members,
another group has 10 members and another group 12
2010 Dec 08
1
sd() for numeric row entries
How might one calculate standard deviation, row-wise, for the numeric values in a data frame such as this one
V1 V2 V3 V4 V5
1 rs11089130 0.4565 0.4574 0.4569 0.4572
2 rs738829 0.6548 0.6519 0.6448 0.6549
3 rs915674 0.7503 0.7500 0.7517 0.7502
and place the standard deviation in a 6th column called “std_dev”?
Regards,
Jim
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2012 May 19
1
Contingency table and mean(sd)
Hi All,
I have a question regarding contingency tables. I would like to calculate the mean and standard deviation of a continuous variable from my own dataset based on the percentages of a contingency table I obtained from a scientific article.
dataset<- data.frame(cbind(case=rep(0:1,5), x1=c(1:10), x2=c(0:9)))
contingency_table<- matrix(c(100, 75, 65, 85, 90, 87), nrow=3, ncol=3)
In
2012 Mar 23
2
plot a BARPLOT with sd deviation bar up and down
dear Researchers,
i am looking for a function to plot a barplot for each mean value and the
related standard deviation, and i can close my week. This is an example of
my data set.
really Thanks in advance for any help or suggestions
Gianni
My.mean <- data.frame(Mean=c(0.4108926,0.3949009,0.4520346,
0.4091665,0.4664066,0.3048296,0.4297226,0.4056383,
2005 Dec 08
2
'mean' and 'sd' calculations do not match
Dear list,
I am using R 2.1.1 on a Fedora 3 Linux, 32 bit PC.
If I compute the aggregated mean and the standard deviation I get
standard deviation values for factors where the mean was not computed.
It seems to me that this is somehow related to the NA values. But I
don't quite understand what is going wrong?
Could it be related to the data import already? Some of the imported
data got the
2008 Sep 25
0
sd() of column, but for a subset of rows
I would like to take the standard deviation of a column, but only for a
subset of the rows in that column with a given index. The following loop
worked fine when I wanted the mean, but is not working for the standard
deviation:
for (i in 1:length(x[1,])){
a<-tapply(x[,i],x[,2],sd, na.rm=TRUE)
xnew<-cbind(xnew,a)}
I have tried re-defining the sd as follows (as suggested on this board),
2012 May 24
3
Exclude when sd=0
How do I trim a matrix to exclude columns that have no standard deviation?
Thanks,
Chris
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2008 Feb 18
2
Custom Plot - means, SD & 5th-95th% (Plotmeans or Boxplot)?
Any help with this problem would be greatly appreciated:
I need to produce a custom plot i haven't come across in R. Basically, I
want to show means, 1st standard deviation and 5th and 95th percentiles
visually, using something resembling a boxplot. Is it possible to completely
customize a boxplot so that it shows means as the bar (instead of, not as
well as medians), standard deviations at
2011 Sep 04
2
sd help
Hello,
I am getting a strange error while computing standard deviation. If
the do the following I get the answer NA NA. Any help??? Thank you so
much.
a<- cbind()
a<- cbind(a, 5)
a<- cbind(a, 7)
print(sd(a))
If I compute the mean it works fine though i.e., print(mean(a)) works
just fine.
2016 Sep 09
2
R-intro: function 'stderr' and 'sd'
In "An Introduction to R" Version 3.3.1, in "4.2 The function tapply() and ragged arrays", after
stderr <- function(x) sqrt(var(x)/length(x)) ,
there is a note in brackets:
Writing functions will be considered later in [Writing your own functions], and in this case was unnecessary as R also has a builtin function sd().
The part "in this case was unnecessary as R also
2024 Aug 11
1
geom_smooth with sd
Dear community
Using after_stat() I was able to visualise ggplot with standard deviations
instead of a confidence interval as seen in the R help.
p1<-ggplot(data = MS1, aes(x= Jahr, y= QI_A,color=Bio, linetype=Bio)) +
geom_smooth(aes(fill=Bio,
ymax=after_stat(y+se*sqrt(length(y))), ymin=after_stat(y-se*sqrt(y))) ,
method = "lm" , formula = y ~ x +
2012 Nov 10
3
sample mean, variance and SD
hi
could you help me to solve this issue
Question:
Using command rweibull(100,8,15), simulate n = 100 realizations from
Weibull(8; 15) distribution. Using the simulated sample, compute the sample
mean, variance and standard deviation of these observations.
I am trying like this
sim<-rweibull(100,8,15) # simulated sample
SM<-mean(sim) # simulated sample mean
var(sim) # variance
2009 Sep 16
1
error: could not find function "sd"
sselamat wrote:
>
> Hi,
> Everytime I try to get the standard deviation of a vector and enter
> command of sd(x), i get a reply
> Error: could not find function "sd"
> Can someone help me please?
> Thanks.
>
>
Hmmm. Please provide more information, it's hard to imagine how this could
happen.
Results of sessionInfo() ???
Here's the only way I
2007 Jun 18
1
how to obtain the OR and 95%CI with 1 SD change of a continue variable
Dear all,
How to obtain the odds ratio (OR) and 95% confidence interval (CI) with
1 standard deviation (SD) change of a continuous variable in logistic
regression?
for example, to investigate the risk of obesity for stroke. I choose the
happening of stroke (positive) as the dependent variable, and waist
circumference as an independent variable. Then I wanna to obtain the OR
and 95% CI with
2011 Feb 10
1
mean and sd for a Dataframe
hi there,
I need to subtract each value in the dataframe from the mean of the column
and divide by the
standard deviation of the column.
> dim(a)
[1] 22011 52
data2 <- sapply(seq(from = 2, by = 1, length = 50), function(e){
rbind((a[[e]] - mean(a[,e]))/sd(a[,e]))
})
Does this look right????
Any help would be appreciated.
Thanks
RT
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2011 Jul 09
1
Meta-analysis with zero values for mean and sd
Hi!
I want to do a meta-analysis with count data for treatement/control cases.
Mi problem is that I need to use zero values (an informative value) for the
mean and standard deviation for one of the treatement, but R has a
problem: "Studies
with zero values for sd.e or sd.c get no weight in meta-analysis". I can
agroup the case by Family (byvar=Family).
¿anybody help me? Thanks!
>
2016 Sep 13
1
R-intro: function 'stderr' and 'sd'
While you are editing that, you might change its name from 'stderr'
to standardError (or standard_error, etc.) so as not to conflict with
base::stderr().
Bill Dunlap
TIBCO Software
wdunlap tibco.com
On Tue, Sep 13, 2016 at 8:55 AM, Martin Maechler <maechler at stat.math.ethz.ch
> wrote:
> >>>>> Suharto Anggono Suharto Anggono via R-devel <r-devel at
2011 Aug 24
1
boxplot from mean and SD data
Dear all,
I have a dataset of 3 categorical factors, the mean and the standard deviation of each value. I want to use these values to plot a boxplot, grouped by each of the 3 categorical factors (24 boxplots in total). I don't have a clue on how to do the boxplot from mean and SD data already calculated.
Thanks in advance
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