Greetings all,

I finally was able to get OpenMx going on my Mac. I am reading in some data and estimating a very small path model, just to get the hang of things. The syntax is

sciach <- read.table("~/Desktop/sciach.txt",header=TRUE)

require(OpenMx)

# data(sciach)

manifests <- names(sciach)

sciachsimple <- sciach[,c("irtsci", "grades", "probsolv")]

pathmodel <- mxModel("path model",type="RAM",

mxData(observed=sciachsimple,type="raw"),

manifestVars = manifests,

```
mxPath(from="probsolv", to="grades",arrows=1,free=TRUE),
mxPath(from="grades", to="irtsci",arrows=1,free=TRUE),
mxPath(from=c("probsolv", "grades", "irtsci"),
arrows=2,
free=TRUE,
values = c(1, 1, 1),
labels=c("varx", "residual1", "residual2")),
mxPath(from="one",
to=c("probsolv", "grades", "irtsci"),
arrows=1,
free=TRUE,
values=c(1, 1, 1),
labels=c("meanx","beta0grades", "beta0irtsci")))
pathmodelfit <- mxRun(pathmodel)
pathmodelfit@output
```

## summary(mxRun(pathmodel))

The error message I'm getting is

Error: The column name 'challeng' in the observed covariance matrix of the FIML objective function in model 'path model' cannot be found in the dimnames of the data.

> pathmodelfit@output

Error: object 'pathmodelfit' not found

>

> summary(mxRun(pathmodel))

Running path model

Error: The column name 'challeng' in the observed covariance matrix of the FIML objective function in model 'path model' cannot be found in the dimnames of the data.

Error in summary(mxRun(pathmodel)) :

## error in evaluating the argument 'object' in selecting a method for function 'summary'

The variable "challeng" is in the sciach dataset but I thought I correctly selected only the variables I wanted using the line sciachsimple <- sciach[,c("irtsci", "grades", "probsolv")] from above.

Thoughts?

Thanks in advance.

David