Displaying 20 results from an estimated 400 matches similar to: "log-normal distribution and shapiro test"
2004 Nov 17
1
R: log-normal distribution and shapiro test
Hi,
from what you're writing:
"The logaritmic transformation
"shapiro.test(log10(y))" says: W=0.9773, p-value=
2.512e-05." it seems the log-values are not
distributed normally and so original data are not
distributed like a log-normal: the p-value is
extremally small!
Other tests for normality are available in package:
nortest
compare the log-transformation of your ecdf
2004 Dec 02
0
A somewhat off the line question to a log normal distribution
Sigfried,
I am not a statistician, but I have learned that according to the Central Limit Theorem (CLT) sums of random variables, regardless of their form, will tend to be normally distributed. CLT does not require the variables in the sum to come from the same underlying distribution.
Ciao,
Hannu Kahra
Progetti Speciali
Monte Paschi Asset Management SGR S.p.A.
Via San Vittore, 37
IT-20123
2004 Dec 02
1
Re: A somewhat off the line question to a log normal distribution
Dear Siegfried,
I believe your boss is wrong saying that:
>He also tried to explain me that the monthly means
>(based on the daily measurements) must follow a
>log-normal distribution too then over the course of a
year.
every statistician know that increasing the sample
size the sample distribution of the mean is proxy to a
gaussian distribution (Central Limit Theorem)
independently
2010 May 11
0
[Fwd: Re: Plotting log-axis with the exponential base to a plot with the default logarithm base 10]
Is it the tick labels that you want to change?
-----Original Message-----
From: "Elisabeth Bjerke Rastad" <ebr024 at post.uit.no>
To: "r-help at r-project.org" <r-help at r-project.org>
Sent: 5/10/10 11:20 AM
Subject: [R] [Fwd: Re: Plotting log-axis with the exponential base to a plot with the default logarithm base 10]
Hello!
Thank you for answering!
What I am
2010 May 10
2
[Fwd: Re: Plotting log-axis with the exponential base to a plot with the default logarithm base 10]
Hello!
Thank you for answering!
What I am trying to do is to plot my raw values (biomass of different
species) on a logaritmic y-axis with the base of e. When I type "log="y"",
the axis transforms into a logaritmic axis with the base of 10.
Best regards,
Elisabeth
> Dear Elisabeth,
>
> I'm not sure if I have understood your question -- are you trying
> to
2010 May 09
3
Plotting log-axis with the exponential base to a plot with the default logarithm base 10
Hello!
I have a problem which I have tried to solve for several days now..
I have plottet a lineplot.CI in the library "sciplot", and I am trying to
plot it with a logaritmic y-axis (with exponential base).
The problem is that; when I type "log "y"", the axis transforms into the
logaritmic of base 10.
I wonder if someeone could tell me how to specify that I would
2010 May 09
1
Plotting log-axis with the exponential base to a plot wi
Hello Ted!
Thank you a lot for your reply!!!
I will try to explain again; what I want is a logarithmic scaled y-axis
with the base of e (not 10). And the values I would like to use in the
plot are the raw values (not transformed in any way). Do you still think
that the base of log does not matter in this case (wheather it is e or 10
as a base)?
Elisabeth
> On 09-May-10 18:10:27, Elisabeth
2008 Nov 21
1
question about shapiro.test()
Hi all!
I tried to perform Shapiro-Wilk test for my sample of 243 values.
> Us
[1] -10.4 -13.1 -12.2 38.1 -18.8 -13.3 -11.7 29.3 49.7 6.8 12.7 16.3
[13] 5.8 -0.7 -29.4 4.1 38.8 -1.4 8.8 15.6 32.9 -5.3 19.1 35.8
[25] 4.0 -1.5 0.6 -4.2 -10.0 -4.0 1.1 48.9 -21.0 -5.3 5.8 -10.8
[37] 21.9 8.2 -3.2 -3.9 -2.3 12.6 -4.7 -8.0 11.8 27.4 -9.5 -20.8
[49]
2007 Nov 21
1
fitting a line to a logaritmic plot
Hi,
I have processed measurements of a rough surface to a heigh-height
correlation plot. What the meaning of this exactly is, is not important.
Only that it is a plot that had two (almost ) linear parts when plotted on a
logaritmic scale. In this plot, I want to draw the best fitting lines for
these linear parts but I just can't get it done. It is easy when the scales
are linear but as you
2009 Jun 18
1
lattice logaritmic scale (basis "e" ), rewriting labels using xscale.component
Hi there,
sorry for troubling everybody once again, I've got a problem rewriting
Sarkar's function for
rewriting the tick locations in a logaritmic way (s.
http://lmdvr.r-forge.r-project.org/code/Chapter08.R):
His example works for log 2 but I need log e (natural logarithm). My
problem is that if I replace
2 with "e" (using paste()), I get the error message that the location
2004 Jan 20
2
avas and ace
Hi,
Does any one know how we can decide on the correct transformation in (avas and ace) after having drawn the graphs y,g(y) x ,s(x) and g(y) ,s(x) . Is it possible by only looking at patterns the graphs follow for example when
y ,g(y) shows a logaritmic pattern can we say that log transform on y is suitable?
Thanks for your help.
Regards
[[alternative HTML version deleted]]
2003 May 18
1
log scale y axis ticks control?
Hello R Users!
I'm using lattice to produce some graphs with logaritmic y-scales. I use
the command
xyplot(hits ~ c(1:1024), data=eichData, type="S", scales=list(y =
list(log=10)))
to create the plot. This is fine, except for the automatically choosen
tick marks. I'd like to have a major tick at the 10^n location and minor
ticks in between which correspond with the native
2006 Feb 27
1
log scale y axis ticks control on boxplots
Hey R Users
I like to control the ticks and labels in a boxplot as described for a
xyplot below (thread in maillinglist in may 2003). Does anybody knows
how it works?
Thanks in advance
Thomas
Thread from May 2003
(http://tolstoy.newcastle.edu.au/R/help/03a/5604.html)
Hello R Users!
I'm using lattice to produce some graphs with logaritmic y-scales. I use
the command
xyplot(hits ~
2009 Jul 25
1
yaxp problem for more irregular time series in one plot
Good day,
I'm trying to get more time series in one plot. As there are bigger
differences in values of variables I need logaritmic y axis.
The code I use is the following:
nvz_3_data <- read.csv('/home/tomas/R_outputs/nvz_3.csv')
date <- (nvz_3_data$date)
NO3 <- (nvz_3_data$NO3)
NH4 <- (nvz_3_data$NH4)
date_p <- as.POSIXct(date, "CET")
par(mfrow=c(2,1), ylog
2007 Apr 01
0
optimize calculations
Hi,
I have a model, which has a logaritmic response, but there is an offset for this response.
I use optimize to find a value to minimise the residuals of the model:
f2 <- function(x,df) sum(summary(lm(log((y-x)/Mnd) ~ I(1e+05/(8.617*(Temp + 273.16))), df))$residuals^2)
start <- optimize(f2,c(0,min(y)),df=df)$minimum
mod <- lm(log((y-start)/Mnd) ~ I(1e+05/(8.617*(Temp + 273.16))), df)
2007 Nov 01
0
density calculation
Hello,
I have another, more statistic related question.
I have several different measurements as an output of an image analysis process
(e.g. size, intensity, ... of objects of interests).
Now, I would like to quantify the difference for each parameter measured in a
special condition comparing to the measurement of a reference condition.
If I plot the density distribution (simply calling
2009 Oct 22
1
Automatization of non-linear regression
Hi everybody,
I'm using the method described here to make a linear regression:
http://www.apsnet.org/education/advancedplantpath/topics/Rmodules/Doc1/05_Nonlinear_regression.html
> ## Input the data that include the variables time, plant ID, and severity
> time <- c(seq(0,10),seq(0,10),seq(0,10))
> plant <- c(rep(1,11),rep(2,11),rep(3,11))
>
> ## Severity
2001 Feb 05
1
clipped lines have wrong slope in log plot (PR#839)
Hi,
I'm using R version 1.2.0 (2000-12-15), on RedHat Linux 6.2 (kernel 2.2.14).
The following command ought to plot a straight-line on a log-log
graph but instead plots two line segments, both with the wrong
slope:
plot(c(1,10,100),c(100,10,1),type="l",xlim=c(1,20),ylim=c(1,20),log="xy")
Only clipped lines seem to have this problem. Changing to type "b"
or
2013 Jun 10
1
btrfs-cleaner Blocked on xfstests 068
I''m running into a problem with the btrfs-cleaner thread becoming
blocked on xfstests 068.
The test locks up indefinitely without completing (normally it
finished in about 45 seconds on my test box).
I''ve replicated the issue on 3.10.0_rc5 and the for-linus branch of 3.9.0.
I ran a git bisect on the 3.9.0 for-linus branch, and tracked my issue
to the following commit:
commit
2010 Mar 16
1
mean(trim=, c(NA,...), na.rm=FALSE) does not return NA
Both of the following should return NA,
but do not in "R version 2.11.0 Under
development (unstable) (2010-03-07 r51225)"
on 32-bit Windows:
> mean(c(1,10,100,NA), trim=.1)
Error in sort.int(x, partial = unique(c(lo, hi))) :
index 4 outside bounds
> mean(c(1,10,100,NA), trim=.26)
[1] 55
With na.rm=TRUE they give the correct results.
(mean() would be so much simpler