[R] robumeta package - error

[Kristina Loderer]

Dear all,

I am trying to fit a simple (intercept-only) meta-analytic model using
the robumeta package using the following code: 
 anx_cont_mean<-robu(formula = es_fisher ~ 1, var.eff.size =
variance_fisher, studynum = study_ID, modelweights = "CORR", rho = 0.8,
small=TRUE, data = anxiety_control)

When I try to run this model, the following error message pops up: 
Error in solve.default(sumXWX) : 
  system is computationally singular: reciprocal condition number = 0

What exactly does this mean in the context of meta-analysis? I haven't
been able to find any answers.

Thank you,
Kristina


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Kristina Loderer
Ludwig-Maximilians-Universität München
Department Psychologie
Leopoldstr. 13
D-80802 München

Telefon: +49 (89) 2180-6047
Email: Kristina.Loderer at psy.lmu.de

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