Displaying 20 results from an estimated 130 matches similar to: "time series questions (corrected)?"
2005 Feb 11
0
time series questions?
Two time series questions:
FITTING TRANSFER FUNCTIONS WITH LAGS: Consider the following toy example:
> dates <- paste(11:21, "/01/2005", sep="")
> Dates <- as.Date(dates, "%d/%m/%Y")
> set.seed(1)
> DF <- data.frame(date=Dates, y=rnorm(11), x=rnorm(11, 3))
> arima(DF$y, c(1,0,0), xreg=lag(DF$x, 1))
ar1 intercept lag(DF$x,
2008 May 21
1
split character string in matrix into character vector and numeric vector
Hello,
I've got a matrix consisting of one column with n rows. Each field in
the matrix is filled with a character vector.
I would like to convert this matrix into a character vector containing
the B03_MAH-type entries from the beginning of each row and a data.frame
that contains the numeric data, but I am stuck.
I have tried to use textConnection with sep = " " but since
2011 Aug 26
2
cbind giving NA's?
I have two xts objects, call them "a" and "b", and am trying to merge them...
> class(a)
[1] "xts" "zoo"
> class(b)
[1] "xts" "zoo"
> head(a)
2010-04-01 7.6343
2010-04-02 7.6343
2010-04-03 7.5458
2010-04-04 7.4532
2010-04-05 7.4040
2010-04-06 7.3317
> head(b)
2010-04-01 568.80
2010-04-05 571.01
2010-04-06
2005 Nov 10
1
converting a character string to a subscripted numeric variable
Dear R-helpers:
It seems that I have a mental block. (Some say that it sits atop my
shoulders.)
For reasons too tedious to retell I have an R object:
> input.line[7]
[1] "-13.24, -11.24, -9.24, -7.24, -5.24, -3.24, -1.24, 0.76, 2.76, 4.76,
6.76, 8.76, 10.76, 12.76, 14.76, 16.76, 18.76, 20.76, 22.76, 24.76, 26.76,
28.76, 30.76, 32.76, 34.76, 36.76, 38.76, 40.76, 42.76, 44.76, "
2003 Nov 03
2
Odd r-squared
Hi,
I would consider the calculation of r-squared in the following to be a
bug, but then, I've been wrong before. It seems that R looks to see if the
model contains an intercept term, and if it does not, computes r-squared in
a way I don't understand. To my mind, the following are two alternative
parametrizations of the same model, and should yield the same r-squared.
Any insight much
2004 Oct 16
3
Lazy loading... advices
Hello,
I am looking for more information about lazy loading introduced in R 2.0.0.
Doing
?lazyLoad
I got some and there is a 'see also' section that points to
'makeLazyLoading'... But I cannot reach this page.
My problem is: I recompiled a library that uses a lot of functions from
other libraries (of course I can give details if needed). I load it in my
computer: library(svGUI),
2004 Jan 12
1
extract data from a data.frame
Hi,
I'm reading part of a table from postgres, so I'm
getting a data frame.
how can I extract the numerica values so I can
operate on them.
> res <- dbGetResult(mydata)
> str(res)
`data.frame': 5 obs. of 8 variables:
$ cyx.1: num 0.149 -0.278 0.114 0.060 0.109
$ cyx.2: num 0.158 -0.070 0.063 0.149 0.150
$ cyx.3: num 0.052 -0.350 0.114 0.126 0.238
2009 May 05
2
Stepwise logistic Regression with significance testing - stepAIC
Hello R-Users,
I have one binary dependent variable and a set of independent variables (glm(formula,…,family=”binomial”) ) and I am using the function stepAIC (“MASS”) for choosing an optimal model. However I am not sure if stepAIC considers significance properties like Likelihood ratio test and Wald test (see example below).
> y <- rbinom(30,1,0.4)
> x1 <- rnorm(30)
> x2
2011 Aug 08
0
Odp: Fw: R function for Gage R&R
Hi Elaine
I do not use it very often. I programmed it to mimic Minitab functions
(partly) with some adons from czech statistics textbook written by
M.Meloun (meloun militky statistics - first hit in google)
Basically you can have your data in some data frame or they can be as
separated vectors. The function itself expects input of 3 vectors, but you
can easily to modify it for imput as
2006 Dec 05
1
Spearman correlation ties and discrepancies
Hi. I am currently trying to run some Spearman correlations, and have
encountered two issues.
1) When using cor.test() with a variable that includes ties, I get the
"Cannot compute exact p-values with ties" error. I have read that this
function now uses an asymptotic formula that allows for ties, so do not
understand why I am getting this error. (I am running version 2.4.0.)
I
2010 Apr 01
2
About logistic regression
Hi,
I have a dichotomous variable (Q1) whose answers are Yes or
No.
Also I have 2 categorical explanatory variables (V1 and V2)
with two levels each.
I used logistic regression to determine whether there is an
effect of V1, V2 or an interaction between them.
I used the R and SAS, just for the conference. It happens
that there is disagreement about the effect of the
explanatory variables
2006 Nov 14
2
Repeated measures by lme and aov give different results
I am analyzing data from an experiment with two factors: Carbon (+/-)
and O3 (+/-), with 4 replicates of each treatment, and 4 harvests over a
year. The treatments are assigned in a block design to individual
Rings.
I have approaches this as a repeated measures design. Fixed factors
are Carbon, O3 and Harvest, with Ring assigned as a random variable. I
have performed repeated measures analysis
2007 Feb 06
2
How to do "moran's I test"?
I want to do "moran's I test" in R language. I try to use "gearymoran" in
Package "ade4","moran" in Package "spdep", and Moran.I in Package "ape". But
I do not know how to do it because data format is different.
My data:
x y dbh
111.03 10.7 7
118.11 0.28 1.2
165.36 0.36 8.4
2004 Feb 04
3
[PATCH] Adding ocfs support to blkid
The following patch adds ocfs support to blkid.
--rusty
# This is a BitKeeper generated patch for the following project:
# Project Name: Ext2 filesystem utilities
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.1327 -> 1.1328
# lib/blkid/probe.c 1.15 -> 1.16
#
2011 Sep 28
1
survexp with large dataframes
Hello, and thank you in advance.
I would like to capture the expected survival from a coxph model for
subjects in an observational study with recurrent events, but the
survexp statement is failing due to memory. I am using R version
2.13.1 (2011-07-08) on Windows XP.
My objective is to plot the fitted survival with the Kaplan-Meier
plot. Below is the code with output and [unfortunately]
2014 Sep 01
1
Correlation Matrix with a Covariate
R Help -
I'm trying to run a correlation matrix with a covariate of "age" and will
at some point will also want to covary other variables concurrently.
I'm using the "psych" package and have tried other methods such as writing
a loop to extract semi-partial correlations, but it does not seem to be
working. How can I accomplish this?
library(psych)
> set.cor(y =
2008 Jul 07
1
GLM, LMER, GEE interpretation
Hi, my dependent variable is a proportion ("prob.bind"), and the independent
variables are factors for group membership ("group") and a covariate
("capacity"). I am interested in the effects of group, capacity, and their
interaction. Each subject is observed on all (4) levels of capacity (I use
capacity as a covariate because the effect of this variable is normatively
2008 Oct 26
0
LMER quasibinomial
Hi,
a while ago I posted a question regarding the use of alternative models,
including a quasibinomial mixed-effects model (see Results 1). I rerun the
exact same model yesterday using R 2.7.2 and lme4_0.999375-26 (see Results
2) and today using R 2.7.2 and lme4_0.999375-27 (see Results 3).
While the coefficient estimates are basically the same in all three
regressions, the estimated standard
2008 Dec 07
1
Reading txt file in R
Hi:
I am using the following code to read a data set in txt in R and using the follwoing model. But it seems to give me an error ' expected variable name error pos 134022'. Any help is greatly appreciated.
Code:
anal.data <- read.table("nausea.txt", header=T, sep="\t")
list(names(anal.data))
attach(anal.data)
n.samples <- dim(anal.data) [1] # number of data
2007 Jan 30
2
R and S-Plus got the different results of principal component analysis from SAS, why?
Dear Rusers,
I have met a difficult problem on explaining the differences of principal
component analysis(PCA) between R,S-PLUS and SAS/STATA/SPSS, which wasn't
met before.
Althought they have got the same eigenvalues, their coeffiecients were
different.
First, I list my results from R,S-PLUS and SAS/STATA/SPSS, and then show
the original dataset, hoping sb. to try and explain it.