Displaying 20 results from an estimated 10000 matches similar to: "sequence that counts up and back down"
2009 Jan 23
5
Stat textbook recommendations?
Hello,
I'm looking for a textbook that can explain some of the math behind
the intro-to-intermediate stuff like ANOVA, multiple regression, non-
parametric tests, etc.
A little background: I took an intro stats course last year and
would like to further my education. Being as that was the highest
(and only) stats class the local community college offers, it looks
like I'm on
2009 Nov 13
1
CentOS lists now searchable via MarkMail.org
Hello,
Just thought I'd drop a note here... a short while ago I was searching
for some info on CentOS, and having been exposed to markmail.org via the
R-project <www.r-project.org> <www.r-project.org>I went to markmail to
do some digging. At that time, they didn't carry the CentOS lists yet,
but after a simple request, now they do. The interface lends itself more
to
2009 Nov 08
3
Some basic LVM questions
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<body bgcolor="#ffffff" text="#000000">
<font size="+1">Hello all,<br>
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I've been 'away' from all things Linux in general and RH in particular
for a long while, so I've got some catching up to do
2009 Jan 18
1
regression model selection
Hello,
Newbie here, be gentle ;)
I have a reference book that discusses regression model selection using
several methods - what they call 'Forward Model Selection' i.e. add one
variable at a time and examining R, R^2, Mallow's C-p value, etc., 'Backward
Model Selection' i.e. starting out with all the variables included and then
remove them one at a time, and examining for
2010 Oct 22
2
create sequence of numbers
Hello.
I want to create some sequence of numbers . So far I used sequence which does
not work always
seq(CRagent[[1]]$xy[1],CRagent[[2]]$xy[1],by=0.01)
Error in seq.default(CRagent[[1]]$xy[1], CRagent[[2]]$xy[1], by = 0.01) :
wrong sign in 'by' argument
Calls: seq -> seq.default
if the parameters are in descending form.
The ideal would be to be able to use seq like this
2011 Nov 02
1
Generate a sequence of vectors of different length
Hi everyone
After the following setup
sector=2 # Define Number of Sectors
sectors=LETTERS[seq( from = 1, to = sector )] # Name sectors
No_ent=round(3/runif(sector)) # Number of entities per sector
#Tot_No_ent=sum(No_ent)
Goal is to get a List like
(A1, A2, A3, B1, B2, B3, B4) where A is denoting an industrial sector and
then a numbered sequence of companies within the sector.
The step
2003 Jan 16
3
Announce: pmg -- menu driven GUI using RGtk
Hello all,
I've put together a quick and dirty menubar + dialogs + spreadsheet
GUI for R using the RGtk package. Performance is not great (OOP is a
real memory hog?), the design may be worse, but the hope is that it
will be useful in an introductory stats course while we await the
arrival of a real gui with ObveRsive and SciViews.
The package can be found at
2003 Jan 16
3
Announce: pmg -- menu driven GUI using RGtk
Hello all,
I've put together a quick and dirty menubar + dialogs + spreadsheet
GUI for R using the RGtk package. Performance is not great (OOP is a
real memory hog?), the design may be worse, but the hope is that it
will be useful in an introductory stats course while we await the
arrival of a real gui with ObveRsive and SciViews.
The package can be found at
2010 Nov 09
3
Row-wise recurive function call
Dear Group,
I have a following dataset:
> a
A B C D
1 22 3 31 40
2 26 31 36 32
3 3 7 49 16
4 24 40 27 26
5 20 45 47 0
6 34 43 11 18
7 48 48 24 2
8 3 16 39 48
9 20 49 7 21
10 17 36 47 10
> dput(a)
structure(list(A = c(22L, 26L, 3L, 24L, 20L, 34L, 48L, 3L, 20L,
17L), B = c(3L, 31L, 7L, 40L, 45L, 43L, 48L, 16L, 49L, 36L),
C = c(31L, 36L, 49L, 27L, 47L, 11L, 24L,
2012 Apr 20
3
Matrix multiplication by multple constants
Dear R helpers
Suppose
x <- c(1:3)
y <- matrix(1:12, ncol = 3, nrow = 4)
> y
[,1] [,2] [,3]
[1,] 1 5 9
[2,] 2 6 10
[3,] 3 7 11
[4,] 4 8 12
I wish to multiply 1st column of y by first element of x i.e. 1, 2nd column of y by 2nd element of x i.e. 2 an so on. Thus the resultant matrix should be like
> z
[,1] [,2] [,3]
[1,] 1
2010 Mar 05
3
how to make this sequence: 1,2,3,4,5,4,3,2,1
I'm just beginning R, with book Using R for Introductory Statistics, and one
of the early questions has me baffled. The question is, create the
sequence: 1,2,3,4,5,4,3,2,1 using seq() and rep().
Now, as a programmer, I am punching myself to not be able to figure it out..
I mean, as simple as a for loop, but using seq, I am stumped. I would think
c(1:5, 4:1) would be the brute force method
2009 Feb 17
2
Efficient matrix computations
Hi,
I am looking for two ways to speed up my computations:
1. Is there a function that efficiently computes the 'sandwich product' of
three matrices, say, ZPZ'
2. Is there a function that efficiently computes the determinant of a
positive definite symmetric matrix?
Thanks,
S.A.
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2008 Sep 17
5
Loop on vector name
[My previous message rejected, therefore I am sending same one with some modification]
I have 3 vectors with object name : dat1, dat2, dat3
Now I want to create a loop, like :
for (i in 1:3)
{
cat(sd(dati))
}
How I can do this in R?
Regards,
2010 Oct 17
4
Variable name as string
Hello,
from Verzani, simpleR (pdf), p. 80, I created the following function to
test the coefficient of lm() against an arbitrary value.
coeff.test <- function(lm.result, var, coeffname, value) {
# null hypothesis: coeff = value
# alternative hypothesis: coeff != value
es <- resid(lm.result)
coeff <- (coefficients(lm.result))[[coeffname]]
# degrees of freedom = length(var) -
2009 Sep 14
4
local sequence function
hey,
I can not find a function for the following problem, hopefully you can
help me.
I have a vactor like this one
v = c(NA,NA,TRUE,TRUE,NA,TRUE,NA,TRUE,TRUE,TRUE)
and I would like to the TRUE values by the their "local sequence
number".
This means, the result should look thike this:
c(NA,NA,1,2,NA,1,NA,1,2,3)
Of course I could solve the problems using a loop, but this would be
2010 Jul 26
2
Concatenate a mix of numbers and letters to create a vector name
Dear all,
I am trying to create a vector name, for example tmax.195012 from tmax., 1950 and 12. Obviously I don't wish to simply type it because the 3 name components are changing in each iteration within a loop. Is there any way of concatenating those 3 components (which are a mixture of numbers and letters)?
Thanks for reading,
Panos
2011 Aug 23
4
Correlation discrepancy
Dear R list, I have one very elementary question regrading correlation between two variables.
x = c(44,46,46,47,45,43,45,44)
y = c(44,43,41,41,46,48,44,43)
> cov(x, y)
[1] -2.428571
However, if I try to calculate the covariance using the formula as
covariance = sum((x-mean(x))*(y-mean(y)))/8 # no of of paired obs. = 8
or
covariance = sum(x*y)/8-(mean(x)*mean(y))
gives
2001 Jul 25
2
pch with plot and legend
I'm trying to plot a scatterplot of two variables using pch to plot
different characters based on a third factor. Here is my example
> data("ToothGrowth")
> attach(ToothGrowth)
> levels(supp)
[1] "OJ" "VC"
> plot(len ~ dose,pch=as.numeric(supp))
> legend(locator(1),pch=as.numeric(supp),legend=levels(supp))
The command as.numeric(supp) returns 2 2
2010 Mar 09
3
Removing Zeros from matrix
Hi Everybody,
I have a matrix of about 45 columns. Some of the rows contain zeros. Using
>data1<-data[complete.cases(data),], I can remove the "NA" rows. But I am
unable to tackle that of zeros.
Can anybody give me an idea of how to remove rows containing zeros in a
matrix.
Thanks so much
Best
Ogbos
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2008 Oct 14
4
request: How to ignore columns having zero sums
Dear friends
I have an array consist of r-rows and c-columns e.g.
x=c(1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,0,0,0,0,0,0,0,0);
x1=array(x, dim=c(4,6))
output is
> x1
[,1] [,2] [,3] [,4] [,5] [,6]
[1,] 1 2 3 4 0 0
[2,] 1 2 3 4 0 0
[3,] 1 2 3 4 0 0
[4,] 1 2 3 4 0 0
How can i ignore columns having zero sums? Help in this regard