Hi all, I want to fit the following model to my data: Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t i.e. it is an ARMA(2,2) with some additional regressors X and M. [Z_t's are the white noise variables] So, I run the following code: for (i in 1:rep) { index=sample(4,15,replace=T) final<-do.call(rbind,lapply(index,function(i) get(as.character(levels[as.numeric(levels)==i])))) --------------------------------> this gives me my data set l=final$l g=final$g model=arima0(l,order=c(2,0,2),xreg=g,method=("ML")) } I get warnings like: Call: arima0(x = l, order = c(2, 0, 2), xreg = g, method = ("ML")) Coefficients: ar1 ar2 ma1 ma2 intercept xreg 0.2549 -0.7722 -0.5586 0.3563 3e-04 0 s.e. 0.1072 0.0866 1.6725 0.2221 2e-04 NaN sigma^2 estimated as 3.921e-06: log likelihood = 311.72, aic = -609.44 Warning message: In sqrt(diag(x$var.coef)) : NaNs produced What does this output mean? How do I get rid of this and do my analysis properly? Any help is welcome. Thanks, Preetam -- Preetam Pal (+91)-9432212774 M-Stat 2nd Year, Room No. N-114 Statistics Division, C.V.Raman Hall Indian Statistical Institute, B.H.O.S. Kolkata. [[alternative HTML version deleted]]
Jose Iparraguirre
2013-May-02 12:07 UTC
[R] warnings in ARMA with other regressor variables
Preetam, Have a look at this post: http://stats.stackexchange.com/questions/26999/auto-arima-warns-nans-produced-on-std-error Jos? -----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf Of Preetam Pal Sent: 02 May 2013 12:24 To: r-help at r-project.org Subject: [R] warnings in ARMA with other regressor variables Hi all, I want to fit the following model to my data: Y_t= a+bY_(t-1)+cY_(t-2) + Z_t +Z_(t-1) + Z_(t-2) + X_t + M_t i.e. it is an ARMA(2,2) with some additional regressors X and M. [Z_t's are the white noise variables] So, I run the following code: for (i in 1:rep) { index=sample(4,15,replace=T) final<-do.call(rbind,lapply(index,function(i) get(as.character(levels[as.numeric(levels)==i])))) --------------------------------> this gives me my data set l=final$l g=final$g model=arima0(l,order=c(2,0,2),xreg=g,method=("ML")) } I get warnings like: Call: arima0(x = l, order = c(2, 0, 2), xreg = g, method = ("ML")) Coefficients: ar1 ar2 ma1 ma2 intercept xreg 0.2549 -0.7722 -0.5586 0.3563 3e-04 0 s.e. 0.1072 0.0866 1.6725 0.2221 2e-04 NaN sigma^2 estimated as 3.921e-06: log likelihood = 311.72, aic = -609.44 Warning message: In sqrt(diag(x$var.coef)) : NaNs produced What does this output mean? How do I get rid of this and do my analysis properly? Any help is welcome. Thanks, Preetam -- Preetam Pal (+91)-9432212774 M-Stat 2nd Year, Room No. N-114 Statistics Division, C.V.Raman Hall Indian Statistical Institute, B.H.O.S. Kolkata. [[alternative HTML version deleted]] ______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Please donate to the Syria Crisis Appeal by text or online: To donate ?5 by mobile, text SYRIA to 70800. To donate online, please visit http://www.ageinternational.org.uk/syria Over one million refugees are desperately in need of water, food, healthcare, warm clothing, blankets and shelter; Age International urgently needs your support to help affected older refugees. Age International is a subsidiary charity of Age UK and a member of the Disasters Emergency Committee (DEC). The DEC launches and co-ordinates national fundraising appeals for public donations on behalf of its member agencies. Texts cost ?5 plus one standard rate message. Age International will receive a minimum of ?4.96. More info at ageinternational.org.uk/SyriaTerms ------------------------------- Age UK is a registered charity and company limited by guarantee, (registered charity number 1128267, registered company number 6825798). Registered office: Tavis House, 1-6 Tavistock Square, London WC1H 9NA. For the purposes of promoting Age UK Insurance, Age UK is an Appointed Representative of Age UK Enterprises Limited, Age UK is an Introducer Appointed Representative of JLT Benefit Solutions Limited and Simplyhealth Access for the purposes of introducing potential annuity and health cash plans customers respectively. Age UK Enterprises Limited, JLT Benefit Solutions Limited and Simplyhealth Access are all authorised and regulated by the Financial Services Authority. ------------------------------ This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you receive a message in error, please advise the sender and delete immediately. Except where this email is sent in the usual course of our business, any opinions expressed in this email are those of the author and do not necessarily reflect the opinions of Age UK or its subsidiaries and associated companies. Age UK monitors all e-mail transmissions passing through its network and may block or modify mails which are deemed to be unsuitable. Age Concern England (charity number 261794) and Help the Aged (charity number 272786) and their trading and other associated companies merged on 1st April 2009. Together they have formed the Age UK Group, dedicated to improving the lives of people in later life. The three national Age Concerns in Scotland, Northern Ireland and Wales have also merged with Help the Aged in these nations to form three registered charities: Age Scotland, Age NI, Age Cymru.