PROC TRAJ statement-options;

MODEL; VAR; INDEP; ORDER; ID; START; WEIGHT; RISK; TCOV; PLOTTCOV;
MIN; MAX; RORDER;     /* cnorm options */
IORDER; EXPOS;        /* zip options */

MODEL2; VAR2; INDEP2; ORDER2; RISK2; TCOV2; PLOTTCOV2;/*JointModel*/
MIN2; MAX2;           /* cnorm options */
IORDER2; EXPOS2;      /* zip options */

PROC TRAJ  DATA=ONE  OUT=OF  OUTPLOT=OP  OUTSTAT=OS  OUTEST=OE  ITDETAIL;

INPUT NAME: 

Specify DATA= data for analysis, e.g. DATA=ONE.

OUTPUT NAMES::

OUT= Group assignments and membership probabilities, e.g. OUT=OF.

OUTSTAT= Parameter estimates used by TRAJPLOT macro, e.g. OUTSTAT=OS.

OUTPLOT= Trajectory plot data, e.g. OUTPLOT=OP.

OUTEST= Parameter and covariance matrix estimates, e.g. OUTEST=OE.

OUTSTAT2=  (joint models) Parameter estimates used by the TRAJPLOT macro for the second model graph, e.g. OUTSTAT2=OS2.

OUTPLOT2= (joint models) Trajectory plot data for the second model graph, e.g. OUTPLOT2=OP2.

ADDITIONAL OPTIONS:

ITDETAIL displays minimization iterations for monitoring model fitting progress.

ALTSTART provides a second default start value strategy.

MODEL; Dependent variable distribution (CNORM, ZIP, LOGIT) e.g. MODEL CNORM;

VAR; Dependent variables, measured at different times or ages (for example, hyperactivity score measured at age t,) e.g. VAR V1-V8;

INDEP; Independent variables (e.g. age, time) when the dependent (VAR) variables were measured, e.g. INDEP T1-T8;

MIN; (CNORM) Minimum for censoring, e.g. MIN 1; If omitted, MIN defaults to zero.

MAX; (CNORM) Maximum for censoring, e.g. MAX 6; If omitted, MAX defaults to +infinity.

ORDER; Polynomial (0=intercept, 1=linear, 2=quadratic, 3=cubic) for each group, e.g. ORDER 2 2 2 0; If omitted, cubics are used by default.

RORDER; (CNORM) Random growth curve parameters (-1=none, 0=intercept, 1=linear, 2=quadratic, 3=cubic) for each group.  For one set of random growth curve parameters, common to the groups, specify a single value. E.g. RORDER 0; or RORDER 0 0 0 0;

IORDER; (ZIP) Polynomial (0=intercept, 1=linear, or 2=quadratic) zero inflation probability logit for each group. For usual Poisson modeling, specify -1 for any group. For one inflation function common to the groups, specify one value in the IORDER statement. E.g. IORDER 1 1 1 1; or IORDER 2;

EXPOS; (ZIP) Exposure variables, e.g. EXPOS E1-E8;

START; Parameter starting values, e.g. START 1.10234  2.22309  1.34718    -.30128  .31274  1.12349   4.12311 .72918  -.36547  20 30 50;

RISK; Factors affecting the probability of group membership, e.g. RISK EDLEVEL;

TCOV; Time varying covariates specified in sets, e.g. TCOV C1-C8; or TCOV C1-C8 D1-D8 E1-E8;

PLOTTCOV; Values for time varying covariates to calculate group trajectories. The number of values needs to be the same as the number of variables in the TCOV statement, e.g. PLOTTCOV 0 0 0 0 1 1 1 1; or PLOTTCOV 0 0 0 0 1 1 1 1  1 1 1 1 0 0 0 0  1 1 1 1 1 1 0 0;

ID; Variables (typically containing information to identify observations) to place in the output (OUT=) data set, e.g. ID IDNO;

WEIGHT; Weight variable for a weighted likelihood function. The covariance matrix is adjusted using a sandwich estimator. E.g. WEIGHT WGT;

Joint Model: MODEL2; VAR2; INDEP2; MIN2; MAX2; ORDER2; IORDER2; EXPOS2; RISK2; TCOV2; PLOTTCOV2;

Required: MODEL, VAR, INDEP (MODEL2, VAR2, INDEP2 for joint models.)

Optional: MIN, MAX, ORDER, RORDER, IORDER, EXPOS, START, TCOV, PLOTTCOV, ID, WEIGHT

Modified 09/20/05 Bobby L. Jones

Contact: Bob by Email