similar to: time series questions (corrected)?

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.