Displaying 20 results from an estimated 2000 matches similar to: "chisq warning"
2005 Aug 08
1
chisq.test
Hi
I am trying to use this function. Can anyone show me how I would input
the following example?
Chi-Squared = (40-30)^2 + (20-30)^2 + (30-30)^2
30 30 30
= 3.333 + 3.333 + 0 = 6.666 (p value = 0.036)
I want to be able to use different denominators so can you show me how I
can do it to accommodate these rather than assuming they are all the
2005 Aug 26
2
chisq.,test`
Hi
I am trying to do this:
chisq.test(c(11, 13, 12, 18, 21, 43, 15, 12, 9, 10, 5, 28, 22, 11, 15,
11, 18, 28, 16, 8, 15, 19, 44, 18, 11, 23, 15, 23, 2, 5, 4, 14, 3, 22,
9, 0, 6, 19, 15, 32, 3, 16, 14, 10, 24, 16, 24, 31, 29, 28, 16, 26, 11,
11, 4, 17, 16, 13, 20, 26, 16, 19, 34, 19, 17, 14, 22, 25, 17, 12, 23,
14, 19, 30, 18, 10, 23, 21, 17, 16, 10, 14, 6, 17, 17, 10, 21, 25, 20,
4, 11, 4,
2005 Oct 25
1
selecting every nth item in the data
I want to make a glm and then use predict. I have a fairly small sample
(4000 cases) and I want to train on 90% and test on 10% but I want to do
it in slices so I test on every 10th case and train on the others. Is
there some simple way to get these elements?
Stephen
--
21/10/2005
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2008 Nov 16
3
chisq.test with simulate.p.value=TRUE (PR#13292)
Full_Name: Reginaldo Constantino
Version: 2.8.0
OS: Ubuntu Hardy (32 bit, kernel 2.6.24)
Submission from: (NULL) (189.61.88.2)
For many tables, chisq.test with simulate.p.value=TRUE gives a p value that is
obviously incorrect and inversely proportional to the number of replicates:
> data(HairEyeColor)
> x <- margin.table(HairEyeColor, c(1, 2))
>
2005 Jan 05
2
plotting percent of incidents within different 'bins'
Hi
Say I have some data, two columns in a table being a binary outcome plus
a predictor and I want to plot a graph that shows the percentage
positives of the binary outcome within bands of the predictor, e.g.
Outcome predictor
0 1
1 2
1 2
0 3
0 3
0
2005 Jun 10
1
logistic regressioin - course ornotes
Hi
I am using R for logistic regression and finding it very useful.
However, I wondered if anyone could point me to any course or notes on
this subject using R.
All help most welcome.
Stephen
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2005 Jun 16
1
logistic regression - using polys and products of features
Hi
I can get all my features by doing this:
> logistic.model = glm(similarity ~ ., family=binomial, data =
cData[3001:3800,])
I can get the product of all my features by this:
logistic.model = glm(similarity ~ . ^ 2, family=binomial, data =
cData[3001:3800,])
I don't seem to be able to get polys by doing this:
logistic.model = glm(similarity ~ poly(.,2), family=binomial, data
2005 Apr 27
1
making table() work
I am trying to do some verification across a large dataset, cuData, that
has 23 columns.
Column 23 (similarity) is the outcome 0 or 1 and the other columns are
the features.
I do this:
verificationglm.model <- glm(formula = similarity ~ ., family=binomial,
data=cuData[1:1000,])
and produce the model:
> summary(verificationglm.model)
Call:
glm(formula = similarity ~ ., family =
2003 Mar 26
3
a statistic question about chisq.test()
Hi,
In the chisq.test(), if the expected frequency for some categories is <5, there will be a warning message which says
Warning message:
Chi-squared approximation may be incorrect in: chisq.test(x, p = probs)
I am wondering whether there are some methods to get rid of this mistake... Seems the ?chisq.test() doesn''t provide more
options to solve this problem. Or, the only choice is
2003 Dec 09
2
p-value from chisq.test working strangely on 1.8.1
Hello everybody,
I'm seeing some strange behavior on R 1.8.1 on Intel/Linux compiled
with gcc 3.2.2. The p-value calculated from the chisq.test function is
incorrect for some input values:
> chisq.test(matrix(c(0, 1, 1, 12555), 2, 2), simulate.p.value=TRUE)
Pearson's Chi-squared test with simulated p-value (based on 2000
replicates)
data: matrix(c(0, 1, 1,
2003 Jul 15
1
Why two chisq.test p values differ when the contingency table is transposed?
I'm using R1.7.0 runing with Win XP. Thanks,
...Tao
????????????????????????????????????????????????????????
>x
[,1] [,2]
[1,] 149 151
[2,] 1 8
>t(x)
[,1] [,2]
[1,] 149 1
[2,] 151 8
>chisq.test(x, simulate.p.value=T, B=100000)
Pearson's Chi-squared test with simulated p-value (based on 1e+05
replicates)
data: x
X-squared = 5.2001, df =
2008 Feb 07
3
how to calculate chisq value in R
for example, an expression such as chisq(df=1,ncp=0) ?
thanks
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2017 Dec 28
1
Numerical stability in chisq.test
> On 28 Dec 2017, at 13:08 , Kurt Hornik <Kurt.Hornik at wu.ac.at> wrote:
>
>>>>>> Jan Motl writes:
>
>> The chisq.test on line 57 contains following code:
>> STATISTIC <- sum(sort((x - E)^2/E, decreasing = TRUE))
>
> The preceding 2 lines seem relevant:
>
> ## Sorting before summing may look strange, but seems to be
>
2008 Jan 15
2
In chisq.test(x) : Chi-squared approximation may be incorrect
Hello,
I received the following warning when running chi-square;
n Is there a way to catch the 'error' code of 'warning' after run
chisq.test(x)?
n What does this error mean?
Thank you for your help.
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2003 Jul 16
1
The two chisq.test p values differ when the contingency table is transposed! (PR#3486)
Full_Name: Tao Shi
Version: 1.7.0
OS: Windows XP Professional
Submission from: (NULL) (149.142.163.65)
> x
[,1] [,2]
[1,] 149 151
[2,] 1 8
> c2x<-chisq.test(x, simulate.p.value=T, B=100000)$p.value
> for(i in (1:20)){c2x<-c(c2x,chisq.test(x,
simulate.p.value=T,B=100000)$p.value)}
> c2tx<-chisq.test(t(x), simulate.p.value=T, B=100000)$p.value
> for(i in
2006 Dec 02
1
Chi-squared approximation may be incorrect in: chisq.test(x)
I am getting "Chi-squared approximation may be incorrect in:
chisq.test(x)" with the data bleow.
Frequency distribution of number of male offspring in families of size 5.
Number of Male Offspring N
0 518
1 2245
2 4621
3 4753
4 2476
5
2009 May 09
2
need help with chisq
I am very new to R. I have some data from a CVS stored in vdata with 4
columns labeled:
X08, Y08, X09, Y09.
I have created two new "columns" like so:
Z08 <- (vdata$X08-vdata$Y08)
Z09 <- (vdata$X09-vdata$Y09)
I would like to use chisq.test for each "row" and output the p-value
for each in a stored variable. I don't know how to do it. Can you
help?
so far I have
2008 Jan 08
1
A question on chisq.test
Dear all,
I would like to do a goodness-of-fit test on my data to see if they follow a mixture of 2 poisson distributions. I have small numbers for observed values. Most of them <5. The chisq.test gives warning message: Chi-squared approximation may be incorrect in: chisq.test(x , p = prob). However, the option sim=TURE would suppress the warning message. Does that mean with the option
2010 Aug 12
2
Difference in Monte Carlo calculation between chisq.test and fisher.test
Hello all,
I would like to know what the difference is between chisq.test and
fisher.test when using the Monte Carlo method with simulate.p.value=TRUE?
Thank you
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2014 May 07
3
historical significance of Pr(>Chisq) < 2.2e-16
Where does the value 2.2e-16 come from in p-values for chisq tests such
as those
reported below?
> Anova(cm.mod2)
Analysis of Deviance Table (Type II tests)
Response: Freq
LR Chisq Df Pr(>Chisq)
B 11026.2 1 < 2.2e-16 ***
W 7037.5 1 < 2.2e-16 ***
Age 886.6 8 < 2.2e-16 ***
B:W 3025.2 1 < 2.2e-16 ***
B:Age 1130.4 8 < 2.2e-16 ***
W:Age 332.9 8 < 2.2e-16 ***
---
Signif.