Displaying 20 results from an estimated 1000 matches similar to: "What's the T-Value in fisher.test"
2008 Jul 10
1
Interpretation of EXACT Statistical Test in finding the probability as Std. Deviations (SumP)
Okay, so I'm fairly retarded, and asked a question about finding the T-Value
in the Fisher Exact method. I suppose what I'm truly after can best be
explained by the Biddle Consulting site that has a program setup to deal
with this kind of thing. Unfortunately, it is not currently functioning,
and has not been for some time. As a result, I'm trying to figure out how
to do this on my
2009 Jul 17
2
Fisher's exact test
Hi,
I'm trying to run Fisher's Exact test on the data below, but I'm not
sure how interpret the data shown. Can someone tell me what this is
saying? Looking at the numbers it should be that there's no significant
difference between the HDL and LDL, but a p-value of 1 seems high. Is
the low value in the LDL unbound making the test unstable and should I
be using an alternative?
Best
2007 Jul 09
1
help on fisher.test(stats)?
Dear friends,
My dataset have many zeros, so i must use fisher exact test .
Unfortunately, the fisher.test(stats) function fail to do it.
Anybody knows how to do the fisher exact test with many zeros in the
dataset?
My dataset is:
a<-matrix(c(0,1,0,0,0,0,1,0,1,0,0,0,0,1,0,1,1,0,2,1,5,1,1,6,4,4,1,17,2,8,5,7,1,1,24,3,6,1,1,3,2,16,7,4,0,2,4,0,17,0,1,0,0,0,1,2),nrow=8,byrow=TRUE)
data.frame(a)
2013 Mar 19
1
fisher.alpha warnings
I have two vectors (a and b) with counts of animals and wanted to
calculate fisher's alpha:
library(vegan)
a <- c(2043, 1258, 52, 1867, 107, 1624, 2, 157, 210, 402, 5, 107, 267,
2, 13683)
b <- c(2043, 1258, 52, 1867, 107, 1624, 2, 157, 210, 402, 5, 107, 267,
2, 3000)
fisher.alpha(a)
fisher.alpha(b)
fisher.alpha(a) gave the following warnings:
> fisher.alpha(a)
[1] 1.572964
2006 Nov 13
1
hybrid in fisher.test broken?
The hybrid feature in fisher.test looks to me like an excellent way to
analyze my two-way tables. The only problem is that it does not seem
to be implemented. Am I right about this?
An example is pasted below. I note that I get the warning message only
when I shouldn't: for a 2x2 table hybrid seems to be ignored without
warning. In no case does fisher.test seem to be checking Cochran
2009 Mar 21
5
Fisher test problem
Hi, I noted a discrepancy between R and openepi when I ran a fisher test
with the same matrix. In R:
> a=matrix(c(1,2,6,17), nrow=2)
> a
[,1] [,2]
[1,] 1 6
[2,] 2 17
> fisher.test(a, conf.int=T)
Fisher's Exact Test for Count Data
data: a
p-value = 1
alternative hypothesis: true odds ratio is not equal to 1
95 percent confidence interval:
0.02061498
2012 May 11
1
Fisher Test in R
Suppose we have the following data set:
Men Women
Dieting 10 30
Non-dieting 5 60
If I run the Fisher exact test in R then what does alternative = greater (or
less) imply? For example:
mat = matrix(c(10,5,30,60), 2,2)
fisher.test(mat,alternative ="greater")
I get the p-value = 0.01588 and odds ratio = 3.943534. Also, when I flip
the rows of
2003 Apr 22
4
fisher exact vs. simulated chi-square
Dear All,
I have a problem understanding the difference between the outcome of a
fisher exact test and a chi-square test (with simulated p.value).
For some sample data (see below), fisher reports p=.02337. The normal
chi-square test complains about "approximation may be incorrect",
because there is a column with cells with very small values. I
therefore tried the chi-square with
2009 Mar 21
1
Fisher test accuracy in doubt
Hi, I noted a discrepancy between R and openepi when I ran a fisher test with
the same matrix. In R:
> a=matrix(c(1,2,6,17), nrow=2)
> a
[,1] [,2]
[1,] 1 6
[2,] 2 17
> fisher.test(a, conf.int=T)
Fisher's Exact Test for Count Data
data: a
p-value = 1
alternative hypothesis: true odds ratio is not equal to 1
95 percent confidence interval:
0.02061498
2007 May 29
1
Estimate Fisher Information by Hessian from OPTIM
Dear All,
I am trying to find MLE by using "OPTIM" function.
Difficult in differentiating some parameter in my objective function, I
would like to use the returned hessian matrix to yield an estimate of
Fisher's Information matrix.
My question: Since the hessian is calculated by numerical differentiate, is
it a reliable estimate? Otherwise I would have to do a lot of work to
2003 Oct 20
1
bug in fisher test---p-value cannot be Inf (PR#4688)
I just found a bug in fisher.test(). This is rw1080, on windows XP.
A p-value can certainly not be Inf, but:
> religion
Costumbres rel orig
Religion Si Algunas veces Nunca
católica 2121 4700 6234
prot/evan 100 216 2461
otra C 27 67 502
otra 0 0 14
> fisher.test(religion, workspace=2000000)
2011 Nov 17
1
Fisher Exact Test
This mean
First, I am no expert but I am analyzing some marketing data.
I have information on two versions of the same site, and I have data
on the number of times people filled out a form on each version
of the site.
Sample data:
Site 1 Site 2
Filled out form 10 35
Did not fill out form 50
2009 Oct 16
1
How odds ratio is computed in fisher.test()?
I'm wondering how odds ratio is computed. I thought that it is
(n11/n12)/(n21/n22), but it is not what fisher.test() computes. Could
somebody let me know?
> n11=3
> n12=1
> n21=1
> n22=3
>
> n1_=n11+n12
> n2_=n21+n22
>
> n_1=n11+n21
> n_2=n12+n22
>
> x=rbind(c(n11,n12),c(n21,n22))
>
> threshold=dhyper(n11,n1_,n2_,n_1)
>
2006 Jan 12
2
Basis of fisher.test
I want to ascertain the basis of the table ranking,
i.e. the meaning of "extreme", in Fisher's Exact Test
as implemented in 'fisher.test', when applied to RxC
tables which are larger than 2x2.
One can summarise a strategy for the test as
1) For each table compatible with the margins
of the observed table, compute the probability
of this table conditional on the
2002 May 24
1
Fisher
Hello.
I had a big collection of Web pages. Now I have this collection divided into
clusters. Every page can be relevant or not. I made a table:
relevant non relevant
cluster1 1 20
cluster2 0 15
cluster3 3 35
. . .
. . .
. . .
I cluster1 I have 21 Web pages, 1
2007 Mar 31
3
strange fisher.test result
A simple question - using the following fishers test it appears that the P value is significant, but the CI includes 1. Is this result correct?
> data.50p10min <- matrix(c(16,15, 8, 24),nrow=2)
> fisher.test(data.50p10min)
Fisher's Exact Test for Count Data
data: data.50p10min
p-value = 0.03941
alternative hypothesis: true odds ratio is not equal to 1
95
2000 Feb 24
1
fisher.test() in ctest or perhaps uniroot() (PR#455)
fisher.test(matrix(c(1,20,246,6873),2),hybrid=F)
Error in if (f(lower, ...) * f(upper, ...) >= 0) stop("f() values at end
points not of opposite sign") :
missing value where logical needed
Thomas Lumley
Assistant Professor, Biostatistics
University of Washington, Seattle
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-devel mailing list --
2010 May 12
1
read table for Fisher Exact
i have 2 groups i want to compare: group A and group B
each group contains let's say 20 patients
i want to perform a Fisher Exact test on genotype distribution
so, see if there is a sign diff in genotpe frequency/distribution (#AA, #AB,
#BB) between group A and B
not for 1, but for 1000 different genes
my question: how should i build my table so i can do:
test <-
2002 Jun 13
2
fisher.test FEXACT memory bug "should not occur" (PR#1662)
This is a bad bug as reported by Robin Hankin,
it is still in "R-patched" ...
##- From: Robin Hankin <r.hankin@auckland.ac.nz>
##- To: r-help@stat.math.ethz.ch
##- Subject: [R] possum sleeping: thanks and fisher.test() FEXACT error
##- Date: Thu, 13 Jun 2002 16:46:26 +1200
## .....
## Example slighlty modified (MM)
d4 <- matrix(c(0, 0, 0, 0, 0, 0, 3, 0, 1, 0, 0, 0, 0, 0,
2010 May 12
1
fisher's posthock test or fisher's combination test
Hi to all
is there a fisher's post hock test or fisher's combination test in R
available?
Maybe not -- its very easy to do it in excel ...
Kind regards Knut