Displaying 20 results from an estimated 3000 matches similar to: "lapply and list indexing basics"
2010 Mar 08
1
lapply and list indexing basics (after realizing I wasn't previously subscribed...sorry)
I have split my original dataframe to generate a list of dataframes each of
which has 3 columns of factors and a 4th column of numeric data.
I would like to use lapply to apply the fitdistr() function to only the 4th
column (x$isi) of the dataframes in the list.
Is there a way to do this or am I misusing lapply?
As a second solution I tried splitting only the numeric data column to yield
a
2005 Apr 05
1
Fitdistr and likelihood
Hi all,
I'm using the function "fitdistr" (library MASS) to fit a distribution to
given data.
What I have to do further, is getting the log-Likelihood-Value from this
estimation.
Is there any simple possibility to realize it?
Regards, Carsten
2012 Feb 21
3
HELP ERROR Weibull values must be > 0
GUYS,
I NEED HELP WITH ERROR:
library(MASS)
> dados<-read.table("mediaRGinverno.txt",header=FALSE)
> vento50<-fitdistr(dados[[1]],densfun="weibull")
Erro em fitdistr(dados[[1]], densfun = "weibull") :
Weibull values must be > 0
WHY RETURN THIS ERROR? WHAT CAN I DO?
BEST REGARDS
[[alternative HTML version deleted]]
2013 Jan 22
2
Assistant
Good-day Sir,
I am R.Language users but am try to? estimate parameter of beta distribution particular dataset but give this error, which is not clear to me: (Initial value in "vmmin" is not finite)
beta.fit <- fitdistr(data,densfun=dbeta,shape1=value , shape2=value)
kindly assist.
expecting your reply:
2013 Apr 16
2
Strange error with log-normal models
Hi,
I have some data, that when plotted looks very close to a log-normal distribution. My goal is to build a regression model to test how this variable responds to several independent variables.
To do this, I want to use the fitdistr tool from the MASS package to see how well my data fits the actual distribution, and also build a generalized linear model using the glm command.
The summary
2009 Nov 20
2
How to use results of distribution fitting for further processing?
This is probably simple, but I have a hard time finding the solution. Any help greatly appreciated.
I would like to use the results of fitdistr(z,densfun=dweibull,start=list(scale=1,shape=1)) for further processing. How do I assign the values of scale and shape to b and a without manually entering the numbers?
TIA
__________________________________________________________________
2011 May 03
3
fitting distributions using fitdistr (MASS)
Please guide me through to resolve the error message that I get
this is what i have done.
>x1<- rnorm(100,2,1)
>x1fitbeta<-fitdistr(x1,"beta")
Error in fitdistr(x1, "beta") : 'start' must be a named list
Yes, I do understand that sometime for the distribution to converge to the
given set of data, it requires initial parameters of the distribution, to
2005 Nov 17
1
Problem with fitdistr for gamma in R 2.2.0
Dear R developers,
I have encountered strange behaviour of fitdistr for gamma in recent R
build i.e. 2.2.0. I have attached the code for data at the end of this mail
so you can reproduce the problem. In short, I am able to run fitdistr under
2.1.0 without problems, while I get the following error under 2.2.0
(Version 2.2.0 Patched (2005-11-15 r36348))
> fitdistr(otm, "gamma")
Error
2012 Feb 23
3
why is generating the same graph???
Hi,
why my script iss always generating the same graph?when I change the parameters and the name of text file?
library(MASS)
dados<-read.table("inverno.txt",header=FALSE)
vento50<-fitdistr(dados[[1]],densfun="weibull")
png(filename="invernoRG.png",width=800,height=600)
hist(dados[[1]], seq(0, 18, 0.5), prob=TRUE, xlab="Velocidade
2005 Sep 06
2
(no subject)
my problem actually arised with fitting the data to the weibulldistribution,
where it is hard to see, if the proposed parameterestimates make sense.
data1:2743;4678;21427;6194;10286;1505;12811;2161;6853;2625;14542;694;11491;
?? ?? ?? ?? ?? 14924;28640;17097;2136;5308;3477;91301;11488;3860;64114;14334
how am I supposed to know what starting values i have to take?
i get different
2012 Feb 21
5
help error: In dweibull(x, shape, scale, log) : NaNs produzidos
Guys,
I'm having an error when I use the command:
library(MASS)> dados<-read.table("inverno.txt",header=FALSE)> vento50<-fitdistr(dados[[1]],densfun="weibull")Mensagens de aviso perdidas:1: In dweibull(x, shape, scale, log) : NaNs produzidos2: In dweibull(x, shape, scale, log) : NaNs produzidos3: In dweibull(x, shape, scale, log) : NaNs produzidos4: In
2010 Jan 04
3
Extract vector elements until cumsum <= x
Hi All,
I have a vector n, and for each n[i] I want to extract n[i], n[i+1],
n[i+2]..., until the cumulative sum of n[i] and subsequent elements exceeds
a CheckValue, whereupon I move to the next index and repeat.
I am trying to find a Vectorized approach, and have seen similar posts where
filter{stat} and rollmean{zoo} were suggested, but, I haven't been able to
figure a way to use them
2009 Jan 14
1
fitting data
Dear all,
I have a set of data which seem to be distributed almost exponentially but
only on [0;1]. I guess that the probability distribution in this case
would look like
\frac{lambda}{1-e^{-\lambda}) e^{-\lambda x}
I would like to use fitdistr to estimate the value of \lambda.
1) Would it be correct first to find lambda for the exponential distribution and then to substitute it in the formula
2003 Aug 05
1
error message in fitdistr
Hi R lovers
Here is a numerical vector test
> test
[1] 206 53 124 112 92 77 118 75 48 176 90 74 107 126 99 84 114
147 99 114 99 84 99 99 99 99 99 104 1 159 100 53
[33] 132 82 85 106 136 99 110 82 99 99 89 107 99 68 130 99 99
110 99 95 153 93 136 51 103 95 99 72 99 50 110 37
[65] 102 104 92 90 94 99 76 81 109 91 98 96 104 104 93 99 125
89
2006 Oct 11
1
About fitdistr
Dear all,
I would like to estimate the parameters of a mixture of two beta
binomial distributions. I saw the function fitdistr from the MASS
library could be a solution but I have some difficulties. Does anyone
know how to specify to fitdistr another function as these which are
predefined? Or is there any other solution to estimate the parameters?
Thank you in advance
Caroline
2012 Feb 23
1
error in fitdistr
Hi dear,
I want to estimate d.f for Chi-squared distribution:
est.chi[i,]<-c(
fitdistr(as.numeric(data2[,i]),"chi-squared",start=list(df=1))$estimate)Warning
message:In optim(x = c(7.86755, 7.50852, 7.86342, 7.70589, 7.70153,
7.58272, :
one-diml optimization by Nelder-Mead is unreliable:
use "Brent" or optimize() directly
Who can help me to solve this problem?
Best
2012 Mar 13
1
Writing a .pdf file within a function - what do I need to return()?
I am trying to write a function that generates one PDf containing plots from
several .csv files within a directory. When I manually execute the code it
seems to work, but not when it is a function. I think I need to return()
something, but haven't had much luck figuring out what/how.
plot.isi<-function(csv.path="~/project/csv by cell") {
csv.files<-grep('.csv',
2005 Sep 06
2
fitting distributions with R
Dear all
I've got the dataset
data:2743;4678;21427;6194;10286;1505;12811;2161;6853;2625;14542;694;11491;
?? ?? ?? ?? ?? 14924;28640;17097;2136;5308;3477;91301;11488;3860;64114;14334
I know from other testing that it should be possible to fit the data with the
exponentialdistribution. I tried to get parameterestimates for the
exponentialdistribution with R, but as the values
of the parameter
2008 Aug 03
2
Determining model parameters
This may be a begining question. If so, please bear with me.
If I have some data that based on the historgram and other plots it "looks" like a beta distribution. Is there a function or functions within R to help me determine the model parameters for such a distirbution? Similarily for other "common" distirbutions, Poisson(lambda), Chi-Square(degrees of freedom, chi-square
2002 Aug 06
2
Estimating Weibull parameters
Hi R-Community,
I have a vector of Weibull distributed observations and I would like to
estimate the parameters "shape" and "scale" of the Weibull distribution.
Is there a way to do this in R?
Much thanks in advance,
Hagen Schm?ller
--
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Dipl.-Ing. Hagen K. Schm?ller
Institut f?r Elektrische Anlagen und