Greetings all,
Now finally getting Mx to work on my Mac, I'm having a good time putting it through its paces. So, I have a simple model I'm playing with
probsolv -> grades -> irtsci
Below is the syntax and output. It's reading the number of obs correctly and the estimates seem correct. However, I am not getting a value for the LR chi-square test nor the RMSEA and the df seem fairly large considering it should only be 1 df. Thanks in advance. David
>
> sciach <- read.table("~/Desktop/Mx stuff/sciach.txt",header=TRUE)
>
> require(OpenMx)
>
> #data(sciach)
>
> sciachsimple <- sciach[,c("irtsci", "grades", "probsolv")]
>
> manifests <- names(sciachsimple)
>
> 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)
Running path model
> # pathmodelfit@output
>
> summary(mxRun(pathmodel))
Running path model
irtsci grades probsolv
Min. : 4.98 Min. :0.000 Min. : 0.00
1st Qu.:10.90 1st Qu.:2.000 1st Qu.: 7.00
Median :14.50 Median :3.000 Median : 9.00
Mean :14.69 Mean :2.858 Mean : 9.01
3rd Qu.:18.80 3rd Qu.:3.500 3rd Qu.:12.00
Max. :24.90 Max. :4.000 Max. :15.00
name matrix row col Estimate Std.Error
1 A irtsci grades 2.13628016 0.14758041
2 A grades probsolv 0.05409493 0.00729430
3 residual2 S irtsci irtsci 21.36742233 0.88520752
4 residual1 S grades grades 0.80461695 0.03333778
5 varx S probsolv probsolv 12.98102667 0.53787536
6 beta0irtsci M 1 irtsci 8.58666103 0.44305855
7 beta0grades M 1 grades 2.37100192 0.07077779
8 meanx M 1 probsolv 9.00943610 0.10555834
Observed statistics: 3495
Estimated parameters: 8
Degrees of freedom: 3487
-2 log likelihood: 16218.66
Saturated -2 log likelihood: NA
numObs: 1165
Chi-Square: NA
p: NA
AIC (Mx): 9244.662
BIC (Mx): -4200.609
adjusted BIC:
RMSEA: NA
frontend time: 0.2014029 secs
backend time: 3.162092 secs
independent submodels time: 6.508827e-05 secs
wall clock time: 3.36356 secs
cpu time: 3.36356 secs
openmx version number: 0.2.9-1147