SLSQP error msg in univariate Ordinal ACE with age and sex as covariates
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twinAceOrdAgeSex_Script.R | 7.21 KB |
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Hi,
I ran the attached ordinal ACE script with age and sex as covariates, and I noticed that for some of my variables I would get the following error message:
"Error in runHelper(model, frontendStart, intervals, silent, suppressWarnings, :
SLSQP: Failed due to singular matrix E or C in LSQ subproblem or rank-deficient equality constraint subproblem or positive directional derivative in line search "
I'm not quite sure what the error message mean and what I should change, but I did notice that when I only included sex as covariate, the code would be able to run properly. Does it mean something went wrong when I included age as one of the covariates?
Any help will be appreciated! Thank you very much!
A few suggestions
It's generally a good idea to use start values that satisfy any MxConstraints. You have the total variance constrained equal to 1.0. Your start values for
a11
,c11
, ande11
come close to satisfying the constraint, but not exactly. You could try startinge11
at 1 and the other two at zero, for instance.If you include age but run the MxModel with
intervals=FALSE
, does it work? If so, then you know that whatever's going wrong is happening while CIs are being calculated.You could try switching optimizers. If you installed OpenMx from the virginia.edu repository, you can switch from SLSQP to NPSOL with
mxOption(NULL,"Default optimizer","NPSOL")
. A similar command can switch to CSOLNP.Log in or register to post comments
In reply to A few suggestions by AdminRobK
Thanks. Normality assumption?
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In reply to Thanks. Normality assumption? by YiTan
latent normal continuum
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constraints?
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