Mplus VERSION 2.12
MUTHEN & MUTHEN
04/28/2003 1:39 PM
INPUT INSTRUCTIONS
! INPUT FILE FOR EXAMPLE 2 from BG MS # 020404 by C Prescott
TITLE: 2-group Univariate Twin Model for a Binary Variable (DELTA param
DATA: FILE = example1.dat;
VARIABLE: NAMES = famno zyg y1 y2;
USEVARIABLEs = y1 y2;
GROUP = zyg(1=mz 2=dz);
CATEGORICAL = y1 y2;
DEFINE: CUT y1(110); CUT y2(110);
ANALYSIS: TYPE = MEANSTRUCTURE;
PARAM = DELTA; ! default method
MODEL: ! set up default values for all groups
[y1$1 y2$1] (1); ! thresholds
{y1@1 y2@1}; ! fix scaling factors to 1
a1 BY y1*.6 (11); a2 BY y2*.6 (11); ! additive genetic loadings
c1 BY y1*.3 (12); c2 BY y2*.3 (12); ! common envt loadings
[a1-c2@0]; ! fix latent variable means=0
a1-c2@1; ! fix latent variable vars=1
a1-a2 WITH c1-c2@0; ! latent variable correlations
a1 WITH a2@1; c1 WITH c2@1;
MODEL dz: ! parameters which differ from 1st group
a1 WITH a2@0.5;
OUTPUT: SAMP RES STAND;
INPUT READING TERMINATED NORMALLY
2-group Univariate Twin Model for a Binary Variable (DELTA param)
SUMMARY OF ANALYSIS
Number of groups 2
Number of observations
Group MZ 1000
Group DZ 1000
Number of y-variables 2
Number of x-variables 0
Number of continuous latent variables 4
Observed variables in the analysis
Y1 Y2
Grouping variable ZYG
Categorical variables
Y1 Y2
Continuous latent variables in the analysis
A1 A2 C1 C2
Estimator WLSMV
Maximum number of iterations 1000
Convergence criterion 0.500D-04
Parameterization DELTA
Input data file(s)
example1.dat
Input data format FREE
SAMPLE STATISTICS
ESTIMATED SAMPLE STATISTICS FOR MZ
SAMPLE THRESHOLDS
Y1$1 Y2$1
________ ________
1 1.054 1.098
SAMPLE TETRACHORIC CORRELATIONS
Y1 Y2
________ ________
Y1
Y2 0.581
ESTIMATED SAMPLE STATISTICS FOR DZ
SAMPLE THRESHOLDS
Y1$1 Y2$1
________ ________
1 1.094 1.041
SAMPLE TETRACHORIC CORRELATIONS
Y1 Y2
________ ________
Y1
Y2 0.323
THE MODEL ESTIMATION TERMINATED NORMALLY
TESTS OF MODEL FIT
Chi-Square Test of Model Fit
Value 1.126*
Degrees of Freedom 3**
P-Value 0.7705
* The chi-square value for MLM, MLR, MLMV, WLSM and WLSMV cannot be used for
chi-square difference tests. MLM and MLR chi-square difference testing is
described on page 360 in the Mplus User's Guide.
** The degrees of freedom for MLMV and WLSMV are estimated according to
formula 110 (page 358) in the Mplus User's Guide.
Chi-Square Test of Model Fit for the Baseline Model
Value 149.825
Degrees of Freedom 2
P-Value 0.0000
CFI/TLI
CFI 1.000
TLI 1.008
RMSEA (Root Mean Square Error Of Approximation)
Estimate 0.000
WRMR (Weighted Root Mean Square Residual)
Value 0.587
MODEL RESULTS
Estimates S.E. Est./S.E. Std StdYX
Group MZ
A1 BY
Y1 0.718 0.117 6.154 0.718 0.718
A2 BY
Y2 0.718 0.117 6.154 0.718 0.718
C1 BY
Y1 0.255 0.278 0.919 0.255 0.255
C2 BY
Y2 0.255 0.278 0.919 0.255 0.255
A1 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
A2 1.000 0.000 0.000 1.000 1.000
A2 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
C1 WITH
C2 1.000 0.000 0.000 1.000 1.000
Means
A1 0.000 0.000 0.000 0.000 0.000
A2 0.000 0.000 0.000 0.000 0.000
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
Thresholds
Y1$1 1.071 0.027 39.080 1.071 1.071
Y2$1 1.071 0.027 39.080 1.071 1.071
Variances
A1 1.000 0.000 0.000 1.000 1.000
A2 1.000 0.000 0.000 1.000 1.000
C1 1.000 0.000 0.000 1.000 1.000
C2 1.000 0.000 0.000 1.000 1.000
Scales
Y1 1.000 0.000 0.000 1.000 1.000
Y2 1.000 0.000 0.000 1.000 1.000
Group DZ
A1 BY
Y1 0.718 0.117 6.154 0.718 0.718
A2 BY
Y2 0.718 0.117 6.154 0.718 0.718
C1 BY
Y1 0.255 0.278 0.919 0.255 0.255
C2 BY
Y2 0.255 0.278 0.919 0.255 0.255
A1 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
A2 0.500 0.000 0.000 0.500 0.500
A2 WITH
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
C1 WITH
C2 1.000 0.000 0.000 1.000 1.000
Means
A1 0.000 0.000 0.000 0.000 0.000
A2 0.000 0.000 0.000 0.000 0.000
C1 0.000 0.000 0.000 0.000 0.000
C2 0.000 0.000 0.000 0.000 0.000
Thresholds
Y1$1 1.071 0.027 39.080 1.071 1.071
Y2$1 1.071 0.027 39.080 1.071 1.071
Variances
A1 1.000 0.000 0.000 1.000 1.000
A2 1.000 0.000 0.000 1.000 1.000
C1 1.000 0.000 0.000 1.000 1.000
C2 1.000 0.000 0.000 1.000 1.000
Scales
Y1 1.000 0.000 0.000 1.000 1.000
Y2 1.000 0.000 0.000 1.000 1.000
R-SQUARE
Group MZ
Observed Residual
Variable Variance R-Square
Y1 0.419 0.581
Y2 0.419 0.581
Group DZ
Observed Residual
Variable Variance R-Square
Y1 0.419 0.581
Y2 0.419 0.581
RESIDUAL OUTPUT
ESTIMATED MODEL AND RESIDUALS (OBSERVED - ESTIMATED) FOR MZ
Model Estimated Means/Intercepts/Thresholds
Y1$1 Y2$1
________ ________
1 1.071 1.071
Residuals for Means/Intercepts/Thresholds
Y1$1 Y2$1
________ ________
1 -0.017 0.027
Model Estimated Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1
Y2 0.581
Residuals for Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1
Y2 0.000
ESTIMATED MODEL AND RESIDUALS (OBSERVED - ESTIMATED) FOR DZ
Model Estimated Means/Intercepts/Thresholds
Y1$1 Y2$1
________ ________
1 1.071 1.071
Residuals for Means/Intercepts/Thresholds
Y1$1 Y2$1
________ ________
1 0.023 -0.031
Model Estimated Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1
Y2 0.323
Residuals for Covariances/Correlations/Residual Correlations
Y1 Y2
________ ________
Y1
Y2 0.000
Beginning Time: 13:39:37
Ending Time: 13:39:38
Elapsed Time: 00:00:01
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