Displaying 20 results from an estimated 1000 matches similar to: "fitting the gamma cumulative distribution function"
2007 Jun 04
3
test for nested factors
Is there a conventional way to test for nested factors? I.e., if 'a'
and 'b' are lists of same-length factors, does each level specified by
'a' correspond to exactly one level specified by 'b'?
The function below seems to suffice, but I'd be happy to know of a more
succinct solution, if it already exists.
Thanks,
Tim.
---
"%nested.in%" <-
2007 Jun 08
4
logical 'or' on list of vectors
Suppose I have a list of logicals, such as returned by lapply:
Theoph$Dose[1] <- NA
Theoph$Time[2] <- NA
Theoph$conc[3] <- NA
lapply(Theoph,is.na)
Is there a direct way to execute logical "or" across all vectors? The
following gives the desired result, but seems unnecessarily complex.
as.logical(apply(do.call("rbind",lapply(Theoph,is.na)),2,"sum"))
2006 Apr 06
2
prevent reassignment of function names
Hi.
I'm trying to find a systematic way to prevent assignment to names of
existing functions. I've tried reassigning to the assignment operator,
with mixed results. The function definition for "<-" below works as
hoped for the demonstrated assignments to a and c. However, for the
assignment based on the test function, it appears that the formal
argument is not
2007 Sep 27
3
testing the contents of an environment
Suppose I want to delete everything in my working directory that is not
a function. It seems that
sapply(ls(),is.function)
always returns FALSE, because ls() returns objects of mode character.
How do I evaluate is.function(), not on a character string, but on the
object that character string represents?
Thanks,
Tim
2007 Apr 05
1
Extent of time zone vulerability for POSIX date and time classes
Hi.
I frequently convert date and time data to and from character
representations. I'm frustrated with chron, because 'seconds' are
required to create a time object (my input data never has seconds).
More importantly, I cannot make chron print the format 12/30/2006 (which
my output data requires).
I really like the format flexibility of strftime() and strptime(), but
of course
2009 May 30
2
degraded performance with rank()
Hi.
I'm maintaining a package that creates an object that is essentially a
classed version of numeric. I updated recently from 2.7.1 to 2.9.0,
and merges involving my class suddenly took a huge performance hit.
I've traced the problem to something near rank(). From NEWS, it seems
rank() etc. changed in 2.8.0. Methods for xtfrm() are supposed to
help, but I've had no success. There
2013 May 01
1
foreign: write.xport
I see in the archives significant discussion about SAS, CDISC formats etc.
for FDA, but no direct suggestion of adding a write.xport method to the
foreign package. Are there significant barriers to doing so?
[[alternative HTML version deleted]]
2013 Feb 02
1
setGeneric() gives "must supply skeleton" when checking package
r-devel,
In a development version of the CRAN package metrumrg, I write ...
require(reshape)
setGeneric('cast')
setOldClass(c('keyed','data.frame'))
setMethod('cast','keyed', function ...)
The result is satisfactory when sourcing the code directly, but when
checking the package (which has 'reshape' as a dependency in the
DESCRIPTION file) I get
2020 Oct 09
1
Aide pour finaliser ce code
Hello.
Here is my R code. I used the functional data . Now I need to use the
functional data by applying the kernels instead of the xi, yi functions.
Bonjour.
Voici mon code en R . J'ai utiliser les donn?es fonctionnelles . Maintenant
j'ai besoin d'utiliser les donn?es fonctionnelles en appliquant les noyaux
? la place des fontions xi, yi
library(MASS)
2007 Oct 07
1
a function to compute the cumulative distribution function (cdf) of the gamma
Un texte encapsul? et encod? dans un jeu de caract?res inconnu a ?t? nettoy?...
Nom : non disponible
Url : https://stat.ethz.ch/pipermail/r-help/attachments/20071006/065906cc/attachment.pl
2018 Dec 04
3
Bug report: Function ppois(0:20, lambda=0.9) does not generate a non-decreasing result.
Le 04/12/2018 ? 11:27, I?aki Ucar a ?crit?:
> On Tue, 4 Dec 2018 at 11:12, <qweytr1 at mail.ustc.edu.cn> wrote:
>> function ppois is a function calculate the CDF of Poisson distribution, it should generate a non-decreasing result, but what I got is:
>>
>>> any(diff(ppois(0:19,lambda=0.9))<0)
>> [1] TRUE
>>
>> Actually,
>>
>>>
2003 May 08
1
function to compute entropy
Maybe its slightly off-topic, but can anybody
help with computing entropy on matrix of probabilities?
Guess we have a matrix of probabilites, A, 2x2, something
like this:
z
x 0 1 2 3 4
0 0.063 0.018 0.019 0.016 0.000
1 0.011 0.162 0.040 0.042 0.003
2 0.015 0.030 0.164 0.033 0.002
3 0.012 0.035 0.036 0.159 0.002
4 0.004 0.021 0.018 0.013 0.082
sum(A)=1
Can i
2008 Jul 01
2
Prediction with Bayesian Network?
Hi,
I am interested in using a bayesian network as a predictor (machine
learning); however, I can't get any of the implementations (deal, nblearn)
to learn & predict stuff.
Shouldn't there also be probabilites for each node after the learning phase,
how can I access these?
Cheers,
Stephan
--
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2018 May 03
1
MCMCglmm - metric of the estimates
Hi,
my question is probably amateurish but I can't seem to find the answer
anywhere.
In what metric are the MCMCglmm package's posterior means for family =
"categorical"?
I suppose that they can't be odds ratios and probabilites as my numbers are
outside their bounds. So I'm thinking ? are they just basic regression
coefficients conceptually equal to those obtained by
2011 Aug 26
1
Predictions from a logistic regression model with validation for ROCR
Dear experts,
I am looking for a package that does logistic regression with corssvalidation and gives me the probabilites of all the corssvalidations so that I can plot them in ROCR.
Would also like to know if the corssvalidate model would give me a summary coefficient for the intercept and my to predictors.
Thank you.
Best regards,
Jon Toledo, MD
Postdoctoral fellow
University of Pennsylvania
2009 Jul 10
2
predict.glm -> which class does it predict?
Hi,
I have a question about logistic regression in R.
Suppose I have a small list of proteins P1, P2, P3 that predict a
two-class target T, say cancer/noncancer. Lets further say I know that I
can build a simple logistic regression model in R
model <- glm(T ~ ., data=d.f(Y), family=binomial) (Y is the dataset of
the Proteins).
This works fine. T is a factored vector with levels cancer,
2004 Oct 09
2
Is it safe? Cochran etc
I have the following contingency table
dat <- matrix(c(1,506,13714,878702),nr=2)
And I want to test if their is an association between events
A:{a,not(a)} and B:{b,not(b)}
| b | not(b) |
--------+-----+--------+
a | 1 | 13714 |
--------+-----+--------+
not(a) | 506 | 878702 |
--------+-----+--------+
I am worried that prop.test and chisq.test are not valid given the
2009 Aug 22
1
Trying something for fun...
Hi,
For fun, I'm trying to throw some horse racing data into either an svm
or lrm model. Curious to see what comes out as there are so many
published papers on this.
One thing I don't know how to do is to standardize the probabilities by
race.
For example, if I train an LRM on a bunch of variable I get a model. I
can then get probability predictions from the model. That works.
2012 Apr 27
1
Handling Negative value due to logarithm of probabilities.
Hi,
In continuation of the discussion of melange comments,about negative value
returned in matcher due to logarithm of probabilities.
*I**f we make K suitably large, we could clamp each log(K.Pi) to be >= 0,
and this change will only affect really low probability terms (those with
Pi < 1/K, so you can adjust K to suit):*
*W' = sum(i=1,...,n, max(log(K.Pi), 0))*
Did you mean for low
2009 May 07
1
data transformation using gamma
Hi R-users,
I have this code to uniformise the data using gamma:
> length(dp1)
[1] 696
> dim(dp1)
[1] 58 12
> dim(ahall)
[1] 1 12
> dim(bhall)
[1] 1 12
> trans_dt <- function(dt,a,b)
+ { n1 <- ncol(dt)
+ n2 <- length(dt)
+ trans <- vector(mode='numeric', length=n2)
+ dim(trans) <- dim(dt)
+ for (i in 1:n1)
+ { dt[,i] <- as.vector(dt[,i])