Displaying 20 results from an estimated 2000 matches similar to: "insignificant factors in regression model"
2006 Feb 28
3
any more direct-search optimization method in R
Hello list,
I am dealing with a noisy function (gradient,hessian not available) with
simple boundary constraints (x_i>0). I've tried constrOptim() using nelder
mead to minimize it but it is way too slow and the returned results are not
satisfying. simulated annealing is so hard to tune and it always crashes R
program in my case. I wonder if there are any packages or functions can do
2004 Sep 09
1
Blom's approximation to rankits?
Hello,
My name is Lisa and I'm a statistician at Princess Margare Hospital. I
wonder if there is any function in R that calculate the Normal rankits
based on Blom's approximation?
Thank you very much
Lisa Wang Msc.
Princess Margaret hospital
Toronto, Ca
2004 May 20
1
Spearman probabilities and SuppDists
cor.test and SuppDists give me different P-values for the same
Spearman's rho. Which is correct, or am I doing something wrong?
> x <- c(44.4, 45.9, 41.9, 53.3, 44.7, 44.1, 50.7, 45.2, 60.1)
> y <- c( 2.6, 3.1, 2.5, 5.0, 3.6, 4.0, 5.2, 2.8, 3.8)
> cor.test(x,y,method="spearman")
Spearman's rank correlation rho
data: x and y
S = 48, p-value =
2004 Jul 27
3
ghyper package
Hello
I am searching ghyper package (generalized hypergeometric distributions).
Does anyone can send it to me?
Regards from Mexico
Lizbeth Román
[[alternative HTML version deleted]]
2006 Jan 10
2
expected values of order statistics
Hello,
Could somebody point me, is there any function in R which returns
expected values of order statistics for normal distribution? I have been
looking and couldn't find it.
Thanks!
Anna
2005 Jan 20
2
Johnson transformation
Hello,
I'm Carla, an italian student, I'm looking for a package to transform non normal data to normality. I tried to use Box Cox, but it's not ok. There is a package to use Johnson families' transormation? Can you give me any suggestions to find free software as R that use this trasform?
Thank yuo very much
Carla
____________________________________________________________
6X
2005 Feb 21
2
power.anova.test for interaction effects
This question will probably get me in trouble on theoretical grounds, but I
will pose it anyway.
The situation:
I recently ran a field study looking for differences in sugarbeet cultivar
tolerance to a specific herbicide. The study was set up so that 37
cultivars were treated with 4 different applications of the herbicide (37*4
factorial). In doing so, we found that the interaction effect was
2005 Dec 21
2
Random numbers
Hi All.
I have R code whose functionality is being replicated within a C+
program. The outputs are to be compared to validate the conversion
somewhat - however (as is always the case) I have stuffed my code with
random number calls.
Random uniform numbers in C+ are being produced using the (Boost)
mersenne-twister generators (mt11213b & mt19937) - which is the default
type of generator
2006 Jan 20
3
fractional factorial design in R
Hi,
i need to create a fractional factorial design sufficient to estimate the
main effects.
The factors may have any number of levels, let's say any number from 2 to 6.
I've tried to use the library conf.design , but i cannot figure out how to
write the code.
For example, what is the code for a design with 5 factors (2x3x3x5x2) and
only main effects not confounded?
thanks in advance!
2010 Aug 21
1
Help Choosing Start Values for nls
Hi all,
I'm trying to do a simple curve fit and coming up with some interesting
results I would like to get comment on.
So as shown below, tsR is my explanatory and response is... well... my
response.
This same data in gnumeric gets fitted with the curve "response=10078.4 +
1358.67 * ln (explanatory - 2009.07)
So I'm using nls with the start values supplied by gnumeric.
in
2005 Sep 14
4
Converting coordinates to actual distances
Hello,
I've been searching for a method of converting Lat/Lon decimal
coordinates into actual distances between points, and taking into
account the curvature of the earth. Is there such a package in R? I've
looked at the GeoR package, but this does not seem to contain what I am
looking for. Ideally the output would be a triangular matrix of
distances.
Thanks in advance,
Paul Brewin
2005 Apr 12
3
where is internal function of sample()?
Hi there,
I am trying to write a c++ shared library for R. I need a function which has
the same functionality as sample() in R, i.e., does permutation, sample
with/without replacement. Does R have internal sample routine so that I can
call it directly?
I did not find it in R.h, Rinternal.h.
Thanks
2004 Sep 15
4
Density Estimation
Hi there,
Sorry if this is a rather loing post. I have a simple list of single
feature data points from which I would like to generate a probability
that an unseen point comes from the same distribution. To do this I am
trying to estimate the probability density of the list of points and
use this to generate a probability for the new unseen points. I have
managed to use the R density function to
2009 Apr 27
2
refit with binomial model (lme4)
Dear R users,
I'm trying to use function 'refit' from lme4
and I get this error that I can't understand:
> refit(dolo4.model4,cbind(uu,50-uu))
Error in function (classes, fdef, mtable) :
unable to find an inherited method for function "refit", for signature
"mer", "matrix"
if I try:
> refit(dolo4.model4,uu)
Error in asMethod(object) :
2002 Dec 18
1
Windows binary of Dopt library
Dear R-helpers,
Would anybody have a compiled binary version (for Windows) of the Dopt
library that is in the development site?.
best regards,
IOsu
--------------------------------------------------------------
Jes?s Mar?a Fr?as Celayeta
Dublin Institute of Technology
School of Food Sci. and Env. Health.
Cathal Bruha St., Dublin 1. Ireland
Phone: +353 1 4024459 Fax: +353 1 4024495
2005 Dec 20
1
nls problem
Hi list,
I tried to use nls to do some nonlinear least square fitting on my data with
340 observations and 10 variables, but as I called nls() function, I got
this error message:
Error in qr.qty(QR, resid) : 'qr' and 'y' must have the same number of rows
Then I traced back a little bit into nls() function, the error seemed to
happen when calling nlsiter() internal function, but
2012 Nov 21
1
update fit (removing insignificant variables)
HI,
I am not sure about the ?update() method.
You could try this:
set.seed(232)
mat1<-matrix(sample(1:100,80,replace=TRUE),ncol=8) #with 8 columns
dat1<-data.frame(mat1)
?names(dat1)[1]<-"Y"
?fit<-lm(Y~.,data=dat1)
res<-coef(summary(fit))
?res
#???????????????? Estimate Std. Error???? t value?? Pr(>|t|)
#(Intercept) 143.763081344 21.9902865? 6.53757200 0.02260698
2004 May 12
1
Sem error - subscript out of bounds
What??s happening with this following code:
require(sem)
Celpe.Mod.RAM <- matrix(c(
# path parametro Inicio
"Produ????o -> T1", "gamma.11", NA,
"Produ????o -> T2", "gamma.12", NA,
2011 Nov 23
2
Correlation matrix removing insignificant R values
Hello.
I have a large dataset with sales pr month for 56 products with 10 months
and i have tried to see how the sales are correlated using
cor()
This has given me a 56X56 matrix with the R value for each product pair.
Most of these correlations are insignificant, and i want only to retain the
instances were the R value is significant (for 10 observations it should be
above 0.64)
Can someone
2009 Jun 13
1
Insignificant variable improves AIC (multinom)?
Hi,
I am trying to specify a multinomial logit model using the multinom function from the nnet package. Now I add another independent variable and it halves the AIC as given by summary(multinom()). But when I call Anova(multinom()) from the car package, it tells me that this added variable is insignificant (Pr(>Chisq)=0.39). Thus, the improved AIC suggests to keep the variable but the Anova