Displaying 20 results from an estimated 8000 matches similar to: "Help : glm p-values for a factor predictor"
2017 Jun 29
0
Help : glm p-values for a factor predictor
It might help if you provided the code you used. It's possible that
you didn't use direction="backward" in stepAIC(). Or if you did, it
was still running, so whatever else you try will still be slow. The
statement "R provides only the pvalues for each level" is wrong: look
at the anova() function.
Bob
On 29 June 2017 at 11:13, Beno?t PELE <benoit.pele at
2017 Jun 29
3
Help : glm p-values for a factor predictor
Hello,
i am a newby on R and i am trying to make a backward selection on a
binomial-logit glm on a large dataset (69000 lines for 145 predictors).
After 3 days working, the stepAIC function did not terminate. I do not
know if that is normal but i would like to try computing a "homemade"
backward with a repeated glm ; at each step, the predictor with the max
pvalue would be
2016 Apr 01
2
p values from GLM
How can I get the p values from a glm ? I want to get the p values so I can add them to a custom report
fitwean<- glm(data[,"JWean"]~data[,"Group"],data=data,family=binomial(link ="logit"))
summary(fitwean) # This lists the coefficeints, SEs, z and p values, but I can't isolate the pvalues.
names(summary(fitwean)) # I see the coefficients,
2016 Apr 01
0
p values from GLM
On 01/04/2016 6:14 PM, John Sorkin wrote:
> How can I get the p values from a glm ? I want to get the p values so
I can add them to a custom report
>
>
> fitwean<-
glm(data[,"JWean"]~data[,"Group"],data=data,family=binomial(link ="logit"))
> summary(fitwean) # This lists the coefficeints, SEs, z
and p values, but I can't
2009 Jan 26
1
glm StepAIC with all interactions and update to remove a term vs. glm specifying all but a few terms and stepAIC
Problem:
I am sorting through model selection process for first time and want to make
sure that I have used glm, stepAIC, and update correctly. Something is
strange because I get a different result between:
1) a glm of 12 predictor variables followed by a stepAIC where all
interactions are considered and then an update to remove one specific
interaction.
vs.
2) entering all the terms
2012 Oct 31
0
combined dependent pvalue
Dear All,
I am trying to combine dependent p-values in R. May you please help me with
this?
For independent pvalue combination, one of the popular way is fisher's
method which I found the R code here
(http://r.789695.n4.nabble.com/fisher-s-posthock-test-or-fisher-s-combination-test-td2195964.html#a2305025):
fisher.comb <- function (pvalues)
{
df=length(pvalues)
2007 Jun 29
1
Shapiro Test P Value Incorrect? (PR#9768)
Full_Name: Jason Polak
Version: R version 2.5.0 (2007-04-23)
OS: Xubuntu 7.04
Submission from: (NULL) (137.122.144.35)
Dear R group,
I have noticed a strange anomaly with the shapiro.test() function. Unfortunately
I do not know how to calculate the shapiro test P values manually so I don't
know if this is an actual bug.
So, to produce the results, run the following code:
pvalues = 0;
for
2004 Apr 06
1
Storing p-values from a glm
Hi,
for example one could do it this way:
v <- summary(fit)$coefficients[,4]
the coefficient attribute is a matrix, and with the "4" you refere to the
pvalue (at least in lm - don't know if summary(glm) produces sligthely
different output).
to skip the intercept (1st row): v <- summary(glmfit)$coefficients[-1,4]
hope this helps,
Arne
--
Arne Muller, Ph.D.
2013 May 16
2
R looping help
Hey I'm not really sure what I should put on here, but I am having trouble
with my R code. I am trying to get the p-values, R^2s etc for a number of
different groups of variables that are all in one dataset.
This is the code:
#Stand counter
st<-1
#Collections
stands<-numeric(67)
slopes<-numeric(67)
intercepts<-numeric(67)
mses<-numeric(67)
rsquares<-numeric(67)
2016 Apr 02
0
p values from GLM
Bert Gunter wrote on 01.04.2016 23:46:
> ... of course, whether one **should** get them is questionable...
>
> http://www.nature.com/news/statisticians-issue-warning-over-misuse-of-p-values-1.19503#/ref-link-1
>
This paper repeats the common place statement that a small p-value does
not necessarily indicate an important finding. Agreed, but maybe I
overlooked examples of important
2017 Jun 06
1
glm and stepAIC selects too many effects
This is a question at the border between stats and r.
When I do a glm with many potential effects, and select a model using
stepAIC, many independent variables are selected even if there are no
relationship between dependent variable and the effects (all are random
numbers).
Do someone has a solution to prevent this effect ? Is it related to
Bonferoni correction ?
Is there is a ratio of
2008 Jan 19
1
How do we get two-tailed p-values for rlm?
How do we get 2-tailed p-values for the rlm summary?
I'm using the following:
> fit <- rlm(oatRT ~ oatoacData$erp, psi=psi.bisquare, maxit=100,
na.action='na.omit')
> fitsum <- summary(fit, cor=F)
> print(fitsum)
Call: rlm(formula = oatRT ~ oatoacData$erp, psi = psi.bisquare, maxit = 100,
na.action = "na.omit")
Residuals:
Min 1Q Median
2013 Jan 09
1
t-test behavior given that the null hypothesis is true
Dear all,
I observer a strange behavior of the pvalues of the t-test under the null
hypothesis. Specifically, I obtain 2 samples of 3 individuals each from a
normal distribution of mean 0 and variance 1. Then, I calculate the pvalue
using the t-test (var.equal=TRUE, samples are independent). When I make a
histogram of pvalues I see that consistently the bin of the smallest
pvalues has a lower
2016 Apr 02
0
p values from GLM
On 01/04/2016 6:46 PM, Bert Gunter wrote:
> ... of course, whether one **should** get them is questionable...
They're just statistics. How could it hurt to look at them?
Duncan Murdoch
>
> http://www.nature.com/news/statisticians-issue-warning-over-misuse-of-p-values-1.19503#/ref-link-1
>
>
> Cheers,
> Bert
>
>
>
> Bert Gunter
>
> "The trouble
2016 Apr 03
0
p values from GLM
How small does a p-value need to be to warrant attention, however?
Witness Fisher?s comment that:
?. . . we may, if we prefer it, draw the line at one in fifty (the 2 per cent point), or one in a hundred (the 1 per cent point). Personally, the writer prefers to set a low standard of significance at the 5 per cent point, and ignore entirely all results which fail to reach this level. A scientific
2013 Jan 09
0
[solved] t-test behavior given that the null hypothesis is true
Hi Ted,
yes this was the problem. Thank you very much.
best
idaios
On Wed, Jan 9, 2013 at 4:51 PM, Ted Harding <Ted.Harding@wlandres.net>wrote:
> Ah! You have aqssigned a parameter "equal.var=TRUE", and "equal.var"
> is not a listed paramater for t.test() -- see ?t.test :
>
> t.test(x, y = NULL,
> alternative = c("two.sided",
2005 Apr 20
1
negative p-values from fisher's test (PR#7801)
Full_Name: Martha Nason
Version: 2.0.1
OS: Windows XP
Submission from: (NULL) (137.187.154.154)
I am running simulations using fisher's test on 2 x c tables and a very small
p.value from fisher's test (<2.2e-16) is returned as a negative number. Code
follows.
> set.seed(0)
> nreps.outer <-7
> pvalue.fisher <- rep(NA,nreps.outer)
>
> population1 <- c(
2017 Aug 23
0
MASS:::dropterm.glm() and MASS:::addterm.glm() should use ... for extractAIC()
Hi,
I have sent this message to this list the July, 7th. It was about a
problem in MASS package.
Until now there is no change in the devel version.
As the problem occurs in a package and not in the R-core, I don't know
if the message should have been sent here. Anyway, I have added a copy
to Pr Ripley.
I hope it could have been fixed.
Sincerely
Marc
Le 09/07/2017 ? 16:05, Marc Girondot via
2010 Nov 22
1
how do remove those predictor which have p value greater than 0.05 in GLM?
Hi R user,
I am a kind of an intermediate user of R. Now I am using GLM model (library
MASS, VEGUS). I used a backward stepwise logistic regression, but i got a
problem in removing those predictors which are above 0.05. I don't want to
include those variables which were above 0.05 in final backward stepwise
logetsic regression model.
for example: first I run the model,
2010 Apr 26
1
Error in pf(q, df1, df2, lower.tail, log.p) : Non-numeric argument to mathematical function
inputfille
snpid indid genotype gvariable probeid gene geneexpression
rs1040480 CHB_NA18524 C/T 2 GI_19743926-I PTPRT 5.850586
rs1040480 CHB_NA18526 C/C 1 GI_19743926-I PTPRT 6.028641
rs1040480 CHB_NA18529 C/C 3 GI_19743926-I PTPRT 5.944392
rs1040481 CHB_NA18532 C/C 1 GI_19743926-I PTPRT 5.938578
rs1040481 CHB_NA18537 C/C 2 GI_19743926-I PTPRT 5.874439
rs1040481 CHB_NA18540 C/C 3 GI_19743926-I