search for: laplace

Displaying 20 results from an estimated 221 matches for "laplace".

2003 Sep 04
2
laplace transform
Dear users, is anybody of you aware of a R command to perform laplace transform or even its inversion? Thank you very much. Luca
2015 Mar 24
2
[LLVMdev] RFC - Improvements to PGO profile support
...: >>> >>> On Tue, Mar 24, 2015 at 1:48 PM, Bob Wilson <bob.wilson at apple.com> wrote: >>>> >>>>> On Mar 24, 2015, at 10:27 AM, Xinliang David Li <davidxl at google.com> wrote: >>>>> >>>>> 2.3) remove the 'laplace rule of succession' which can be very harmful >>>> >>>> I have not seen any consensus on this. I’m not at all convinced this would be a good idea. From what I’ve seen, using LaPlace’s rule avoids really bad behavior in cases where the counts are very small and has almos...
2015 Mar 26
2
[LLVMdev] RFC - Improvements to PGO profile support
...Tue, Mar 24, 2015 at 1:48 PM, Bob Wilson <bob.wilson at apple.com> wrote: >>>>>> >>>>>>> On Mar 24, 2015, at 10:27 AM, Xinliang David Li <davidxl at google.com> wrote: >>>>>>> >>>>>>> 2.3) remove the 'laplace rule of succession' which can be very harmful >>>>>> >>>>>> I have not seen any consensus on this. I’m not at all convinced this would be a good idea. From what I’ve seen, using LaPlace’s rule avoids really bad behavior in cases where the counts are very sma...
2006 Mar 21
1
Is it possible to model with Laplace's error distribution?
Hello! My question is stated in the Subject: Is it possible to model with Laplace's error distribution? For example, lmer() function have few families of functions, like binomial etc., but not Laplace. Is there any other package that would allow for Laplace? Or is there a way to give "user-defined" family? Sincerely, P. Milin
2005 Jun 16
1
identical results with PQL and Laplace options in lmer function (package lme4)
Dear R users I encounter a problem when i perform a generalized linear mixed model (binary data) with the lmer function (package lme4) with R 2.1.0 on windows XP and the latest version of package "lme4" (0.96-1) and "matrix" (0.96-2) both options "PQL" and "Laplace" for the method argument in lmer function gave me the same results (random and fixed effects estimates, standard error and p.values). However, Loglikelihood and deviance are different. here is an example reproduced with the bacteria data set available in the MASS package: library(lme4) libra...
2015 May 07
3
[LLVMdev] RFC - Improvements to PGO profile support
...to get this right, at >> least for real, non-benchmark code. > > We do have a lot of users (real world apps) who can get this right -- > I am not joking ;) > >> >> >> Without the rule, the two workload at least produces consistent >> profile data. With the Laplace rule, you get 50 in one case, and 66 >> in the other. >> >> >> Yes, but you’ve got more information in one case than the other. This is a >> feature IMO, not a bug. It’s entirely possible that with workload 2, the >> loop may have executed for a drastically diffe...
2015 May 07
2
[LLVMdev] RFC - Improvements to PGO profile support
...e. >>> >>> We do have a lot of users (real world apps) who can get this right -- >>> I am not joking ;) >>> >>>> >>>> >>>> Without the rule, the two workload at least produces consistent >>>> profile data. With the Laplace rule, you get 50 in one case, and 66 >>>> in the other. >>>> >>>> >>>> Yes, but you’ve got more information in one case than the other. This is a >>>> feature IMO, not a bug. It’s entirely possible that with workload 2, the >>>&gt...
2007 Jun 01
2
Interaction term in lmer
...dom) + trt*center interaction. Then, I want to compare these 2 models with Likelihood Ratio Test. Here are my lmer codes that I don't feel comfortable about their correctness. model1 <- try(lmer(cbind( yvect, nvect-yvect) ~ 1 + (1 | center), family = binomial, niter = 25, method = "Laplace", control = list(usePQL = FALSE) )) model2 <- try(lmer(cbind( yvect, nvect-yvect) ~ trt*center + ( 1 | center) , family = binomial, niter = 25, method = "Laplace", control = list(usePQL = FALSE) )) (I have attached outputs below) What I don't understand is; I thought...
2005 Nov 28
1
GLMM: measure for significance of random variable?
...t on the model outcome. Does such a measure exist in R? My second question is, if there is a "predict"-function for glmms in R? Because I would like to produce a predictive habitat-map (someone asked that before, but I think there was no answer so far). And the third, why the method "laplace" doesn't work with all my models. thank you very much nina klar R output for a model, which works with laplace: > model4a<-lmer(RESPONSE~ D_TO_FORAL + + I((DIST_WATER-200)*(DIST_WATER<200)) + + I((DIST_VILL-900)*(DIST_VILL<900)) + + (1|TIER), family=binomial, method=&quo...
2008 Nov 01
2
sampling from Laplace-Normal
Hi, I have to draw samples from an asymmetric-Laplace-Normal distribution: f(u|y, x, beta, phi, sigma, tau) \propto exp( - sum( ( abs(lo) + (2*tau-1)*lo )/(2*sigma) ) - 0.5/phi*u^2), where lo = (y - x*beta) and y=(y_1, ..., y_n), x=(x_1, ..., x_n) -- sorry for this huge formula -- A WinBUGS Gibbs sampler and the HI package arms sampler were used with...
2015 Mar 24
2
[LLVMdev] RFC - Improvements to PGO profile support
...go Novillo <dnovillo at google.com> wrote: > > On Tue, Mar 24, 2015 at 1:48 PM, Bob Wilson <bob.wilson at apple.com> wrote: >> >>> On Mar 24, 2015, at 10:27 AM, Xinliang David Li <davidxl at google.com> wrote: >>> >>> 2.3) remove the 'laplace rule of succession' which can be very harmful >> >> I have not seen any consensus on this. I’m not at all convinced this would be a good idea. From what I’ve seen, using LaPlace’s rule avoids really bad behavior in cases where the counts are very small and has almost no impact when...
2007 Nov 30
2
lmer and method call
...~ visit + gender + house + cokefreq + cracfreq + herofreq + borcur + comc + (1 | code), data = vidusGD, family = binomial, correlation = corCompSymm(form = 1 | ID), method = "ML") Although the model fits, the summary indicates the model is a "Generalized linear mixed model fit using Laplace". I've tried any number of permutations; is only Laplace supported in lmer, despite the text of the help file? Thanks for any guidance you might give. M-J -- Research assistant Vancouver Injection Drug User Survey BC Centre for Excellence in HIV/AIDS St. Paul's Hospital, Vancouve...
2008 Jul 06
2
Error: cannot use PQL when using lmer
...acteria) > table(y) y n y 43 177 > y<-1*(y=="y") > table(y,trt) trt y placebo drug drug+ 0 12 18 13 1 84 44 49 > library(lme4) > model1<-lmer(y~trt+(week|ID),family=binomial,method="PQL") Error in match.arg(method, c("Laplace", "AGQ")) : 'arg' should be one of ?Laplace?, ?AGQ?
2010 Nov 24
0
Laplace Approximation
Does anyone have any R code that shows how to do a Laplace Approximation? I know there are a variety of these numerical approximation algorithms and I'm pretty open at this point, I'm just curious how it's approximated in R code. I have seen some functions in packages, but I think they all call C code, and am looking for an example in R only....
2011 Oct 02
0
Multivariate Laplace density
Can anyone show how to calculate a multivariate Laplace density? Thanks. -- View this message in context: http://r.789695.n4.nabble.com/Multivariate-Laplace-density-tp3864072p3864072.html Sent from the R help mailing list archive at Nabble.com.
2007 Oct 12
0
change of variance components depending on scaling of fixed effects
...umber recruits2,number recruits 1), Pop is populations (five level factor) and ja is year (covariate running from 1955-2004). I.e. biologically I am interested to see how the proportion of recruits from the second clutch has changed over time between the different populations. I've used the Laplace optimization method, due to earlier reports of unstability of PQL when running binomial models. First example: (ja covariate range: 1955-2004) > totmod2 <- lmer(p2rec~Pop*ja + (1|VROUW)+(1|ja), data=dltab2, family=binomial, method="Laplace", na.action=na.omit) > summary(tot...
2003 Jun 23
0
Reliability analysis and Laplace factor functions
Is there some package out there that implements functions for reliability analysis, especially for software reliability? In particular, I'm looking for: * Laplace factor (Cox & Lewis 1978) * Goel-Okumoto fitting Thanks in advance, -Ekr -- [Eric Rescorla ekr at rtfm.com]
2010 Mar 11
1
Dicrete Laplace distribution
Hello, <http://tolstoy.newcastle.edu.au/R/help/04/07/0312.html#0313qlink1> Could anybody tell me how to generate discrete Laplacian distribution? I need to sample uma discretised Laplacian density like this: J( g -> g´) ~ exp (-lambda | g´ - g |) g in {0,…, gmax} Thanks, Nicolette [[alternative HTML version deleted]]
2008 Sep 18
1
caret package: arguments passed to the classification or regression routine
Hi, I am having problems passing arguments to method="gbm" using the train() function. I would like to train gbm using the laplace distribution or the quantile distribution. here is the code I used and the error: gbm.test <- train(x.enet, y.matrix[,7], method="gbm", distribution=list(name="quantile",alpha=0.5), verbose=FALSE, trControl=trainControl(method="cv",number=5), tuneGrid...
2006 Jan 27
2
lme4_0.995-2/Matrix_0.995-4 upgrade introduces error messages (change management)
...other attached packages: lme4 lattice Matrix "0.995-2" "0.12-11" "0.995-4" > options(show.signif.stars=FALSE) > m1a<-lmer(cbind(prevented,control.count)~repellant+hour+(1|volunteer)+(1|date), + family=binomial(link='probit'), method='Laplace') Error in dev.resids(y, mu, weights) : argument wt must be a numeric vector of length 1 or length 219 > # probit doesn't converge > m1b<-lmer(cbind(prevented,control.count)~repellant+hour+(1|volunteer)+(1|date), + family=binomial, method='Laplace') Error in dev.resids(y, m...