Error: The name '-2sumll' is illegal

Posted on
No user picture. jarrode28 Joined: 03/01/2010

Hi Everyone,

I've been running basic, univariate twin models over the last week and have had no troubles, but today (March 14) I began receiving the following error in response to this code. The code is nearly identical to the code used at the Twin Workshop, with the exception of different variables and had worked fine up until now even with the new variables. Any ideas of what might be causing this (it seems like a technical issue rather than a modeling issue, but I may be wrong)?

Thanks,
Jarrod

+ mxAlgebra( MZ.objective + DZ.objective, name="-2sumll" ),
+ mxAlgebraObjective("-2sumll")
+ )
Error: The name '-2sumll' is illegal because it contains the '-' character.

Replied on Sun, 03/14/2010 - 17:43
Picture of user. mspiegel Joined: Jul 31, 2009

Yup. All of the following characters are now illegal in names: "+-!~?:*/^%<>=&|$" The reason for this is that these characters can be confused with R operators. Rename the algebra to something like "minus2sumll" and it will work.

Replied on Tue, 03/16/2010 - 13:19
No user picture. jarrode28 Joined: Mar 01, 2010

In reply to by mspiegel

Thanks for the response (it makes sense). However, I am currently getting several additional errors that I previously hadn't (at the time I thought they were all stemming from the initial error in response). Namely, I now get these errors:

> parameterSpecifications(univTwinSatFit)
Error: could not find function "parameterSpecifications"
> expectedMeansCovariances(univTwinSatFit)
Error: could not find function "expectedMeansCovariances"
> tableFitStatistics(univTwinSatFit)
Error: could not find function "tableFitStatistics"

Is there a section on the website I should be checking for changes to the OpenMx package that may help answer these questions (while saving you all some time)?

Replied on Tue, 03/16/2010 - 13:30
Picture of user. mspiegel Joined: Jul 31, 2009

In reply to by jarrode28

These errors appear because the gen_epi helper functions are not loaded into your environment. You need to source( "http://www.vipbg.vcu.edu/~vipbg/Tc24/GenEpiHelperFunctions.R"). WRT your other question, the changelog for OpenMx can be found here. But I'm not sure if it would have helped you track down this particular error.