Displaying 20 results from an estimated 5000 matches similar to: "finding an unknown distribution"
2009 Sep 23
1
re peated measures
Hi,
I am performing a repeated measures 2-way ANOVA to assess the influence of
plant and leaf on aphid fecundity. Fecundity is measured for each aphid on a
single leaf.
Here is what I typed.
wingless <- reshape(Wingless,
varying =
2007 Dec 27
2
groupedData function not found
Hello,
I'm trying to use the groupedData function and R is giving me the message: Error: can not find function "groupedData"
The code is coming from a textbook so I think it should be correct:
pigs<-data.frame(cbind(pig.time,pig.id,pig.wt))
pig.growth<-groupedData(pig.wt~pig.time|pig.id,data=pigs)
I have added the package "nlme" and to confirm that it was installed
2008 Aug 10
2
Differential Equations there use in R (population modeling)
e1 <- function(x,b,t){
d<-(x)*(b^t)
plot(d)
}
e1(2, 2,seq(from=0, to=6, by=1))
Is there a way to do this with a change in time. I would like to use
differential equations. I am trying to model
a population with an initial value, fecundity per time step, and a
death rate. The above simply shows an exponential growth rate. I
would like to model species response like the famous
2008 Mar 25
0
Mixed-effects models: question about the syntax to introduce interactions
hello everyone,
I would like to as for advice for the use of ?lmer?
(package ?lme4?) and writing the proper syntax to best
describe my data using a mixed-effects model.
I have just started to use these models, and although
I have read some good examples (Extending the Linear
Model with R, Faraway 2005; and the R book, Crawley
2007), I am still not sure of the syntax to test my
hypothesis.
2012 Jul 10
1
Revolutions blog: June Roundup
I write about R every weekday at the Revolutions blog:
http://blog.revolutionanalytics.com
and every month I post a summary of articles from the previous month
of particular interest to readers of r-help.
In case you missed them, here are some articles related to R from the
month of June:
The FDA goes on the record that it's OK to use R for drug trials:
http://bit.ly/M0OoqA
A review of
2013 Jun 11
1
calculo de poder estadistico en glm
Hola,
Estoy tratando de calcular el poder estadistico de un GLM en R, programas estadisticos como SPSS lo puede calcular pero no eh encotrado nada sobre R. Alguien tiene alguna idea o sabe de literatura donde pueda encontrar ayuda?
Luego tengo otra pregunta mas bien teorica sobre la funcion offset utilizada en negative poisson, por lo que eh entendido esta funcion posibilita trabajar con
2001 Dec 14
1
nls fit to exponential decay with unknown time origin
I'm trying to use nls() to fit an exponential decay with an unknown offset
in the time (independent variable). (Perhaps this is inherently very
difficult?).
> decay.pl <- nls (amp ~ expn(b0,b1,tau,t0,t), data = decay,
+ start = c(b0=1, b1=7.5, tau=3.5, t0=0.1), trace=T)
Error in nlsModel(formula, mf, start) : singular gradient matrix at
initial parameter estimates
2013 Apr 06
1
Plotting a curve for a Holling Type III Functional Response
Hey,
So I have a scatter plot and I am trying to plot a curve to fit the data
based on a Holling Type III functional response. My function is this:
nll2<-function(a,b) {
conefun<-(a*DBH^2)/(b^2+DBH^2)
nlls2<-dnbinom(x=cones ,size=DBH, mu=conefun,log=TRUE)
-sum(nlls)
}
and my plot is this:
plot (DBH,cones)
DBH is on the x-axis and cones is on the y-axis. How do I get the curve
2008 Jul 02
0
question on dispersion parameter
Hi,
I'm programming in R and below is a summary of a generalized linear model:
************************************************** ***
Call:
glm(formula = offspring ~ degdays, family = quasi(link = "log", variance =
"mu"), data = fecundity)
Deviance Residuals:
Min 1Q Median 3Q Max
-0.76674 -0.29117 -0.09664 0.15668 1.00800
Coefficients:
Estimate Std. Error t value
2011 May 23
0
storing data from loops
Dear R-help list,
I have a problem storing results from a bootstrap loop. What I doing is
creating an empty matrix before the loop, then run the loop. Before the end
of the loop I have a command line which defines which results inside the
loop will have to go in the empty matrix. Here is the code I am using:
eigen.values<-rep(NA,boots)
#storage file for eigen values (1 for simulation)
2011 Jun 14
2
How to generate bivariate exponential distribution?
Any one know is there any package or function to generate bivariate
exponential distribution? I gusee there should be three parameters, two rate
parameters and one correlation parameter. I just did not find any function
available on R. Any suggestion is appreciated.
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2008 Jun 27
1
finding the suitable distribution
Dear R-users,
Attach with is my data..what i want to do is finding a suitable distribution for my data..I want to run a few test like the poisson and the exponential distribution. Please help me on how to find the p-value for poisson as well as the exponential distribution without knowing the parameter. Is it possible?? Thanks in advance.
love,
Anisah
-------------- next
2013 Nov 04
2
transform one probability distribution into another
Hi guys
Given a exponential curve, is there any function on r that can generate exponential distributed random numbers?
in General I want an function that can transform one probability distribution into another??
Regards
******************************************************************
Bander
*************************************
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2007 Aug 28
3
Interpreting the eigen value of a population matrix (2nd try)
Thanks for telling me that you could not get my message, I hope this work
better...
so my question was:
I built a population matrix to which I applied the fonction eigen in order
to find the main parameters about my population. I know that the first
eigen value correspond to lambda or exponential growth rate of my
population. My problem is that I want to have the 95% confidence interval
of the
2011 Apr 04
1
Clarks 2Dt function in R
Dear Ben,
you answerd to Nancy Shackelford about Clarks 2Dt function.
Since the thread ended just after your reply,
I would like to ask, if you have an idea how to use this function in R
I defined it the following way:
function(x , p, u) {
(p/(pi*u))*(1+(x^2/u))^(p+1)
}
and would like to fit this one to my obeservational data (count)
[,1] [,2]
[1,] 15 12
[2,] 45 13
[3,]
2008 Dec 10
1
mixed exponential distribution
Good morning,
Is there anyway to do Mixed Exponential Distribution in R? I am trying
to load some lag-weighted empirical survival distribution into R and run
a mixed exponential on that data.
Thanks,
Jacob Fazekas
Jacob Fazekas
Assistant Actuary
Auto-Owners Insurance Company
517-703-2543
fazekas.jacob@aoins.com
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2011 Mar 21
2
Exponential distribution
Dear R-users,
I have to plot a exponential distribution like the plot in the pdf
attached. I've write this code but I don't know how to draw the two lines..
Can anyone help me please?
Thank you very much
Pippo http://r.789695.n4.nabble.com/file/n3394476/exponential_smoothing.pdf
exponential_smoothing.pdf
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2007 Mar 11
1
fitting a mixed exponential distribution
Hi all,
I am attempting to fit, and test the goodness of fit of, a mixed
exponential distribution to my dataset which consists of 15minute
rainfall intensity data. FYI, the dataset spanning approx.2 years and
7 rainfall stations consists of some three hundred thousand 15min data
records, of which some 30 thousand are non-zero rainfall amounts.
Could anyone please tell me how i could do
2003 Jun 10
2
fitting data to exponential distribution with glm
I am learning glm function, but how do you fit data using exponential
distribution with glm?
In the help file, under "Family Objects for Models", no ready made option
seems available for the distribution as well as for other distributions
satisfying GLM requirements not listed there.
2013 Jun 11
2
calculo de poder estadistico en glm
Estimado Matias,
Reenvio a la lista. Es tarde aqui y hay que descansar. Quizas alguien en
otra parte del mundo pueda darte una mano. En unas horas te envio mi
opinion.
Saludos,
Jorge.-
2013/6/11 Matias Ledesma <>
> Hola Jorge,
>
> Muchas gracias por las referencias, ya consegui el libro asi que me voy
> aponer a leerlo aver si encuentro una solucion.
>
> La data