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Hi, I would like to generate a correlation matrix with a particular structure. For example, a 3n x 3n matrix : A_(nxn) aI_(nxn) bI_(nxn) aI_(nxn) A_(nxn) cI_(nxn) aI_(nxn) cI_(nxn) A_(nxn) where - A_(nxn) is a *specified* symmetric, positive definite nxn matrix. - I_(nxn) is an identity matrix of order n - a, b, c are (any) real numbers Many attempts have been unsuccessful because a

...2PH phone: +44 (0)20 7528 4702 fax: +44 (0)20 7558 3785 >Message: 2 >Date: 12 Dec 2004 14:58:38 +0100 >From: Peter Dalgaard <p.dalgaard at biostat.ku.dk> >Subject: Re: [R] Help : generating correlation matrix with a > particular structure >To: Siew Leng TENG <siewlengteng at yahoo.com> >Cc: r-help at stat.math.ethz.ch >Message-ID: <x2sm6bd3e9.fsf at biostat.ku.dk> >Content-Type: text/plain; charset=us-ascii > >Siew Leng TENG <siewlengteng at yahoo.com> writes: > >> Hi, >> >> I would like to generate a correlation m...

Hi, I am experiencing a baffling behaviour of stepAIC(), and I hope to get any advice/help on this. Greatly appreciate any kind advice given. I am using stepAIC() to, say, select a model via stepwise selection method. R Version : 1.7.1 Windows ME Many thanks! ***Issue : When stepAIC() is placed within a function, it seems that stepAIC() cannot detect the data matrix, and the program is

Hi, I have a data file which contains multiple data types (char and numeric) alongside with line spaces, tabs and spaces. I hope to extract out the numeric blocks of the data, probably as matrices or dataframes where each line in the data block is a corresponding row in the dataframe/ matrix. I have tried using many R read functions but they do not seem to yield the appropriate structure that

Hi, I am experiencing a baffling behaviour of stepAIC(), and I hope to get any advice/help on what went wrong or I'd missed. I greatly appreciate any advice given. I am using stepAIC() to, say, select a model via stepwise selection method. R Version : 1.7.1 Windows ME Many thanks and best regards, Siew-Leng ***Issue : When stepAIC() is placed within a function, it seems

Hi, I am getting errors of the following kind. I can't seem to point the source of the error. I would greatly appreciate any advice. Many thanks and good day, -Melinda Error message : ---------------- "Ran out of iterations and did not converge in: fitter(X, Y, strats, offset, init, control, weights = weights,..." Details : --------- E is a vector of survival times (or censored