Displaying 20 results from an estimated 10000 matches similar to: "Chi-Square test"
2007 Feb 23
2
Wrinting integers in a matrix faile
Hello everyone,
I am using the following program to get the p-value of some numbers
(column 'LR' of the data.dat file). I want to write the 1st and 2nd
column of the output file (data.out) as an integer while the program
change them to double. Could anybody please tell me how I can write
the code which writes the values of the first two columns as integer?
Thanks
library ('MASS')
2007 Feb 25
1
Writing integers in "write.matrix" function
Hello everyone,
I am using the following program to get the p-value of some numbers
(column 'LR' of the data.dat file). I want to write the 1st and 2nd
column of the output file (data.out) as an integer while the program
change them. Could anybody please tell me how I can write
the code which writes the values of the first two columns as integer?
For your convenience, I have attached the
2009 Jul 27
3
numbers on barplot
Hello all,
I have this simple barplot code:
ifn <- "id.dat"
dat <- read.table(ifn)
ofn <- "id.png"
bitmap(ofn, type = "png256", width = 30, height = 30, pointsize = 30, bg =
"white",res=50)
par(mar=c(5, 5, 3, 2),lwd=5)
par(cex.main=1.6,cex.lab=1.6,cex.axis=1.6)
names(dat)<-c("NumberOfPeople","Average")
2006 Oct 02
5
Barplot
Hello,
I have used the following data to draw my barplot:
BL LR Q
36.35 1.00 1.92
36.91 4.00 0.00
25.70 6.00 0.00
34.38 3.00 1.92
05.32 0.50 0.00
BL<-c(36.35, 36.91, 25.70, 34.38, 05.32)
LR<-c(1.00, 4.00, 6.00, 3.00, 0.50)
Q<-<(1.92, 0.00, 0.00, 1.92, 0.00)
barplot(dt$LR, main='LR Value', col='orange', border='black',
2010 Feb 17
2
array question
Hello All:
If I do have:
x = (2, 4, 5, 5, 6, 4, 5, 2, 1)
y = (9, 11.5, 12.5, 13, 14, 19, 20, 21, 22)
I wanted to find a simple function in R which calculates the averages of X
and Y for every 4 unit increase of Y. The results should look like:
x = (4, 6, 3) #where (2+ 4+ 5+ 5)/ 4 = 4 and ...
y = (12, 14, 20.5) #where (9+11.5+12.5+13)/ 4 = 12 and ...
Thanks,
Mohsen
2007 Mar 21
1
any way to append a table in SQL server
Dear Lister,
Is there an interface in R with SQL server that allows me to append
records to table in the DB? Might I do that using RODBC?
Thanks a lot.
--
WenSui Liu
A lousy statistician who happens to know a little programming
(http://spaces.msn.com/statcompute/blog)
2006 Dec 23
7
OT: any recommendation for scripting language
Right now, I am using SAS and S+/R. As a new year resolution, I am
planning to learn a scripting language.
from statisticians' point of view, which scripting language is worth
to learn, perl, python, or any other recommendation? (Most likely, I
will be learning it in windows.) Since I am not in research, I will
prefer one widely used in industry and related to statistical work.
if you
2006 Sep 27
2
Histogram
Dear all,
I want to design a histogram and I need to have the frequency at certain
points. For example I have the following 2 columns:
*X Y*
0.1 25
0.4 22
0.45 11
0.55 21
I want the chart to have 4 columns. First column is from 0.0-0.1 (on X) and
frequency is 25. Next colum is wider and form 0.1-0.4 with 22 frequency.
Next column is narrow with 11 frequency and the last column is
2008 Nov 07
4
chi square table
Hi,
How do we get the value of a chi square as we usually look up on the
table on our text book?
i.e. Chi-square(0.01, df=8), the text book table gives 20.090
> dchisq(0.01, df=8)
[1] 1.036471e-08
> pchisq(0.01, df=8)
[1] 2.593772e-11
> qchisq(0.01, df=8)
[1] 1.646497
>
nono of them give me 20.090
Thanks,
cruz
2010 Jul 21
4
Chi-square distribution probability density function:
Hi to all I found
an formular of an **
***p-Value Calculator for the Chi-Square test*
*http://www.danielsoper.com/statcalc/calc11.aspx*
*with the formula*
*http://www.danielsoper.com/statkb/topic11.aspx*
*what's the gamma function of this formula in r?*
*df=5*
*ch2=25.50878*
*the following code does not give the result <0.001 for the values above *
*p=
2008 Oct 25
2
how to plot chi-square distribution in the graph
if i want to plot the chi-square distribution with a different degree of
freedom how can i plot it in the graph?Sometimes i plot the histogram and
cut it in a lot of piece.It's distribution like a chi-square.So i want to
plot the chi-square with a different degree of freedom to compare it .
--
View this message in context:
2007 Aug 24
1
chi-square statistics
I'm wondering if R has functions to return pvalues with given x-squares and
df. I googled for it but couldn't seem to find one. Appreciate any helps
here.
An example: df=4, x<- c(33.69, 32.96, 30.90) which are the statistic for
chi-square, I'd like to get the corresponding pvalues for each values in x.
Thanks.
-Karen
[[alternative HTML version deleted]]
2008 Jan 07
2
chi-squared with zero df (PR#10551)
Full_Name: Jerry W. Lewis
Version: 2.6.1
OS: Windows XP Professional
Submission from: (NULL) (24.147.191.250)
pchisq(0,0,ncp=lambda) returns 0 instead of exp(-lambda/2)
pchisq(x,0,ncp=lambda) returns NaN instead of exp(-lambda/2)*(1 +
SUM_{r=0}^infty ((lambda/2)^r / r!) pchisq(x, df + 2r))
qchisq(.7,0,ncp=1) returns 1.712252 instead of 0.701297103
qchisq(exp(-1/2),0,ncp=1) returns 1.238938
2006 Dec 01
2
Non central chi squared bug (PR#9406)
Full_Name: Alan Bain
Version: 2.4.0
OS: XP
Submission from: (NULL) (155.140.122.227)
Code for pnchisq contains following
if (tSml) {
if (x> f+ theta+ 5*sqrt(2*(f+2*theta) ))){
return 1.; /* better than 0 --- but definately FIXME */
}
}
This needs to check which tail has been requested; it is only correct if the
default lower_tail=1 has been requested; for upper tail should return 0
2008 Jun 25
1
weighted inverse chi-square method for combining p-values
Hi,
This is more of a general question than a pure R one, but I hope that is OK.
I want to combine one-tailed independent p-values using the weighted version
of fisher's inverse chi-square method. The unweighted version is pretty
straightforward to implement. If x is a vector with p-values, then I guess
that this will do for the unweighted version:
statistic <- -2*sum(log(x))
comb.p <-
2009 Aug 13
1
reading a string
Hello All:
I am having the following data file named "data.dat"
Number of people
Number of pets
Age of trees
ifn <- "data.dat"
dat <- read.table(ifn)
colnames(dat)<-c("Variables")
I want R to read all these in a string but when I ask R to read these,
it gives me error because there more than one word in each line. Any
comments to solve this problem?
2007 Mar 11
3
read.table for a subset of data
Hi R-experts,
I have data from four conditions of an experiment. I tried to create four
subsets of the data with read.table, for example,
read.table("Experiment.csv",subset=(condition=="1"))
. I found a similar post in the archive, but the answer to that post was
no. Any new ideas about reading subsets of data with read.table?
Thanks!
Feng
[[alternative HTML version
2009 Aug 06
2
Ylim
Hello All:
Can anybody tell me what is the problem with my program please. I have an
error message as appears below.
My program is:
ifn <- "Jul08_09.LM"
data <- read.table(ifn)
ofn <- "Jul.png"
bitmap(ofn, type = "png256", width = 30, height = 30, pointsize = 30, bg =
"white",res=50)
par(mar=c(5, 5, 3, 2),lwd=5)
2000 Nov 03
1
Chi-square Goodness of Fit Test
Dear R-users,
is there a function for the Chi-square Goodness of Fit Test in R
(compare function chisq.gof in S/S-PLUS).
Thanks for help.
Matthias Seitzinger
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2007 Jun 27
1
how to use chi-square to test correlation question
Hi There,
There are 300 boy students and 100 girl students in a class. One interesting question is whether
boy is smarter than girl or not.
first given the exam with a difficulty level 1, the number of the student who got A is below
31 for boy, 10 for girl.
Then we increase the difficulty level of the exam to level 2, the number of the student who got A is below
32 for boy, 10 for girl.
We