Displaying 20 results from an estimated 7000 matches similar to: "Overriding contributed package functions"
2004 Nov 15
2
tsdiag() titles
I am using the ts package to fit ARIMA models, and the tsdiag() function to
plot diagnostics. In doing so I'm generating an awful lot of diagnostic
plots of different models and different data sets all within the same R
session. So my question is, is there an option in tsdiag() similar to
<main="Title"> that I can use? This would be quite helpful when I print out
the plots,
2005 Aug 29
1
Different sings for correlations in OLS and TSA
Dear list,
I am trying to re-analyse something. I do have two time series, one
of which (ts.mar) might help explaining the other (ts.anr). In the
original analysis, no-one seems to have cared about the data being
time-series and they just did OLS. This yielded a strong positive
correlation.
I want to know if this correlation is still as strong when the
autocorrelations are taken into account.
2006 Mar 28
1
Having trouble with tsdiag function on a time series
Hello,
I'm getting the following error message when I try to run 'tsdiag' on what seems to be a valid time series:
> tsdiag(small)
returns:
[Error in tsdiag(small) : no applicable method for "tsdiag"]
where small is a little test series where I have isolated this problem (the original has 30-years worth of daily data)
When I print it (small), it looks like the
2010 May 04
1
How to make predictions with the predict() method on an arimax object using arimax() from TSA library
Hi R Users,
I'm fairly new to R (about 3 months use thus far.)
I wanting to use the arimax function from the TSA library to incorporate some exogenous inputs into the basic underllying arima model.Then with that newly model of type arimax, I would like to make a prediction.
To avoid being bogged down with issues specific to my own work, I would like to refer to readers to the example
2009 Feb 03
1
Time series plots with ggplot
Hi,
I am newbie user of ggplot and would like some assistance in
implementing time series plots.
I'd like to know how the tsdiag plot can be made in ggplot?
Thanks
Harsh Singhal
Decisions Systems,
Mu Sigma Inc.
2010 Aug 30
1
How to Remove Autocorrelation from Simple Moving Average time series
Hi R experts,
I am trying to remove autocorrelation from Simple Moving Average time series. I know that this can be done by using seasonal ARIMA like,
library(TTR)
data <- rnorm(252)
n=21
sma_data=SMA(data,n)
sma_data=sma_data[-1:-n]
acf(sma_data,length(sma_data))
2009 Oct 13
1
How to specify an ARMA(1, [1,4]) model?
Hi,
I'm trying to model an ARMA(1,[1,4]),
i.e. I want only lags 1 and 4 of the Moving Average part.
It's the '[1,4]' part that is giving me a problem.
I've tried different arma's and arima's in different packages, namely:
packages tseries, fArma, FinTS, timeSeries, TSA, Zelig, ds1, forecast
For example, with package FinTS:
> ( ARIMA(y, order=c(1,0,c(1,4))) )
2006 Mar 04
1
replicated time series - lme?
Dear R-helpers,
I have a time series analysis problem in R:
I want to analyse the output of my simulation model which is proportional
cover of shrubs in a savanna plot for each of 500 successive years. I have
run the model (which includes stochasticity, especially in the initial
conditions) 17 times generating 17 time series of shrub cover.
I am interested in a possible periodicity of shrub
2012 Mar 29
1
how to increase speed for function?/time efficiency of below function
i am using sarima() function as below
___________________________________________________________________________________________
sarima=function(data,p,d,q,P=0,D=0,Q=0,S=-1,tol=.001){
n=length(data)
constant=1:n
xmean=matrix(1,n,1)
if (d>0 & D>0)
fitit=arima(data, order=c(p,d,q), seasonal=list(order=c(P,D,Q),
period=S),
2013 Feb 21
2
Arimax with intervention dummy and multiple covariates
Hi
I'm trying to measure the effect of a policy intervention (Box and Tiao, 1975).
This query has to do with the coding of the model rather than with the particulars of my dataset, so I'm not providing the actual dataset (or a simulated one) in this case, apart from some general description.
The time series are of length n=34 (annual observations between 1977 and 2010). The policy
2017 Jul 07
1
Scoring and Ranking Methods
Hi,
I am doing predictive modelling of Multivariate Time series Data of a Motor
in R using various models such as Arima, H2O.Randomforest, glmnet, lm and
few other models.
I created a function to select a model of our choice and do prediction.
Model1 <- function(){
..
return()
}
Model2 <- function(){
...
return()
}
Model3 <- function(){
...
return()
}
main <-
2010 May 25
2
summary of arima model in R
Hi,
I want to give a summary or anova for "arima" model in R, as
"summary", and "anova" for "lm".
As including various intervention factors in arima(xreg = ) part, I
want to assess the significancy of thse factors.
I can do it using interrupted analysis of time series by linear
regression, but want to see whether arima model works for the data
first.
2012 Jun 15
1
Replication of linear model/autoregressive model
Hi,
I would like to make a replication of 10 of a linear, first order
Autoregressive function, with respect to the replication of its innovation,
e. for example:
#where e is a random variables of innovation (from GEV distribution-that
explains the rgev)
#by using the arima.sim model from TSA package, I try to produce Y
replicates, with respect to every replicates of e,
#means for e[,1], I want
2008 Oct 15
1
Forecasting using ARIMAX
Dear R-helpers,
I would appreicate if someone can help me on the transfer parameter in ARIMAX and also see what I am doing is correct.
I am using ARIMAX with 2 Exogeneous Variables and 10 years data are as follows:
DepVar Period, depVar, IndepVar1 Period, indepVar1, IndepVar2 Period, indepVar2
Jan 1998,708,Jan 1998,495,Jan 1998,245.490
Feb 1998,670,Feb 1998,421.25,Feb 1998,288.170
Mar
2004 Jul 21
2
Testing autocorrelation & heteroskedasticity of residuals in ts
Hi,
I'm dealing with time series. I usually use stl() to
estimate trend, stagionality and residuals. I test for
normality of residuals using shapiro.test(), but I
can't test for autocorrelation and heteroskedasticity.
Is there a way to perform Durbin-Watson test and
Breusch-Pagan test (or other simalar tests) for time
series?
I find dwtest() and bptest() in the package lmtest,
but it
2008 Mar 21
1
tseries(arma) vs. stats(arima)
Hello,
The "arma" function in the "tseries" package allows estimation of models
with specific "ar" and "ma" lags with its "lag" argument.
For example: y[t] = a[0] + a[1]y[t-3] +b[1]e[t-2] + e[t] can be estimated
with the following specification : arma(y, lag=list(ar=3,ma=2)).
Is this possible with the "arima" function in the
2008 Sep 02
1
installation problem: package 'mgcv' could not be loaded
Hello all, i'm a newbie of R trying to make some statistical work in R
environment. Now i have to laptops, one is Thinkpad X40 with Debian
Lenny and the other is Thinkpad T43 with Ubuntu 8.10. Recently i met
such problem and am wondering if anybody can do some help.
After upgrading my /etc/apt/sources.list , i install R by apt-get
install command. It works fine in both laptops. Then i
2008 Sep 02
1
installation problem: package 'mgcv' could not be loaded
Hello all, i'm a newbie of R trying to make some statistical work in R
environment. Now i have to laptops, one is Thinkpad X40 with Debian
Lenny and the other is Thinkpad T43 with Ubuntu 8.10. Recently i met
such problem and am wondering if anybody can do some help.
After upgrading my /etc/apt/sources.list , i install R by apt-get
install command. It works fine in both laptops. Then i
2012 Aug 03
4
How to concatenate a several rows according with a column ?
Hi, I'm a new user or R and I try to concatenate a several rows according
with the value in a column.
this is my data.frame and I want to concatenate my data.frame according with
the column "b" and make a new data.frame with the information in the others
columns.
>table1
a b c d
1 E001234 TSA IP234 like_domain
2
2012 Jul 03
4
question
I have already fitted several models
using R code; arima(rates,c(p,d,q))
As I heard, best model produce the
smallest AIC value, but maximum likelihood estimation procedure optimizer
should converge.
How to check whether maximum likelihood estimation procedure optimizer has converged or not?
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