Mplus VERSION 6
MUTHEN & MUTHEN
04/25/2010 10:57 PM
INPUT INSTRUCTIONS
! SCRIPT NAME : ctSATut4 (cb)
! GOAL : To calculate tetrachoric correlations
! DATA : ordinal
! INPUT : contingency tables
! UNI/BI/MULTI : uni
! DATA-GROUPS : MZM DZM MZF DZF
! MEANS MODEL : -
! VARIANCE COVARIANCE MODEL(S) :
!1. no model
!2. as 1, plus thresholds same for twin 1 and twin 2
!3. as 2, plus thresholds same for MZ and DZ
!4. as 3, plus thresholds same for males and females but correlations different for
!5. as 4, plus correlations MZM = MZF and DZM = DZF (no sex differences)
!6. as 3, plus correlations MZM = MZF and DZM = DZF but thresholds differ for males
data: file is ct4.dat;
variable: names are g y1 y2 weight;
categorical=y1 y2;
grouping=g(1=MZM 2=DZM 3=MZF 4=DZF); ! specify the two groups MZ and DZ
freqweight=weight;
model:
[y1$1] (mzmt1);
[y2$1] (mzmt2);
y1 with y2 (mzmc);
model dzm:
[y1$1] (dzmt1);
[y2$1] (dzmt2);
y1 with y2 (dzmc);
model mzf:
[y1$1] (mzft1);
[y2$1] (mzft2);
y1 with y2 (mzfc);
model dzf:
[y1$1] (dzft1);
[y2$1] (dzft2);
y1 with y2 (dzfc);
! model test will produce Wald's test for these constraints
model test:
! Uncomment to test equal thresholds for for twin 1 and twin 2
mzmt1 = mzmt2;
dzmt1 = dzmt2;
mzft1 = mzft2;
dzft1 = dzft2;
! Uncomment to test equal thresholds for MZ and DZ
! mzmt1 = dzmt1;
! mzft1 = dzft1;
! Uncomment to test equal thresholds across gender
! mzmt1 = mzft1;
! Uncomment to test no sex differences on correlation
! mzmc = mzfc;
! dzmc = dzfc;
*** WARNING
Input line exceeded 90 characters. Some input may be truncated.
!4. as 3, plus thresholds same for males and females but correlations different for 4 group
*** WARNING
Input line exceeded 90 characters. Some input may be truncated.
!6. as 3, plus correlations MZM = MZF and DZM = DZF but thresholds differ for males and fem
2 WARNING(S) FOUND IN THE INPUT INSTRUCTIONS
SUMMARY OF ANALYSIS
Number of groups 4
Number of observations
Group MZM 243
Group DZM 137
Group MZF 620
Group DZF 317
Number of patterns
Group MZM 4
Group DZM 4
Group MZF 4
Group DZF 4
Number of dependent variables 2
Number of independent variables 0
Number of continuous latent variables 0
Observed dependent variables
Binary and ordered categorical (ordinal)
Y1 Y2
Variables with special functions
Grouping variable G
Weight variable WEIGHT
Estimator WLSMV
Maximum number of iterations 1000
Convergence criterion 0.500D-04
Maximum number of steepest descent iterations 20
Parameterization DELTA
Input data file(s)
ct4.dat
Input data format FREE
UNIVARIATE PROPORTIONS AND COUNTS FOR CATEGORICAL VARIABLES
Group MZM
Y1
Category 1 0.951 231.000
Category 2 0.049 12.000
Y2
Category 1 0.934 227.000
Category 2 0.066 16.000
Group DZM
Y1
Category 1 0.942 129.000
Category 2 0.058 8.000
Y2
Category 1 0.927 127.000
Category 2 0.073 10.000
Group MZF
Y1
Category 1 0.821 509.000
Category 2 0.179 111.000
Y2
Category 1 0.832 516.000
Category 2 0.168 104.000
Group DZF
Y1
Category 1 0.864 274.000
Category 2 0.136 43.000
Y2
Category 1 0.817 259.000
Category 2 0.183 58.000
THE MODEL ESTIMATION TERMINATED NORMALLY
TESTS OF MODEL FIT
Chi-Square Test of Model Fit
Value 0.000*
Degrees of Freedom 0
P-Value 0.0000
Chi-Square Contributions From Each Group
MZM 0.000
DZM 0.000
MZF 0.000
DZF 0.000
* The chi-square value for MLM, MLMV, MLR, ULSMV, WLSM and WLSMV cannot be used
for chi-square difference testing in the regular way. MLM, MLR and WLSM
chi-square difference testing is described on the Mplus website. MLMV, WLSMV,
and ULSMV difference testing is done using the DIFFTEST option.
Chi-Square Test of Model Fit for the Baseline Model
Value 167.776
Degrees of Freedom 4
P-Value 0.0000
CFI/TLI
CFI 1.000
TLI 1.000
Wald Test of Parameter Constraints
Value 4.788
Degrees of Freedom 4
P-Value 0.3098
Number of Free Parameters 12
RMSEA (Root Mean Square Error Of Approximation)
Estimate 0.000
WRMR (Weighted Root Mean Square Residual)
Value 0.011
MODEL RESULTS
Two-Tailed
Estimate S.E. Est./S.E. P-Value
Group MZM
Y1 WITH
Y2 0.651 0.138 4.712 0.000
Thresholds
Y1$1 1.651 0.136 12.129 0.000
Y2$1 1.507 0.124 12.135 0.000
Group DZM
Y1 WITH
Y2 0.153 0.291 0.525 0.599
Thresholds
Y1$1 1.568 0.172 9.130 0.000
Y2$1 1.454 0.160 9.070 0.000
Group MZF
Y1 WITH
Y2 0.646 0.055 11.683 0.000
Thresholds
Y1$1 0.919 0.059 15.610 0.000
Y2$1 0.963 0.060 16.103 0.000
Group DZF
Y1 WITH
Y2 0.333 0.112 2.970 0.003
Thresholds
Y1$1 1.100 0.088 12.460 0.000
Y2$1 0.904 0.082 11.037 0.000
QUALITY OF NUMERICAL RESULTS
Condition Number for the Information Matrix 0.362E-01
(ratio of smallest to largest eigenvalue)
Beginning Time: 22:57:38
Ending Time: 22:57:38
Elapsed Time: 00:00:00
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