Dynamics
Download: Dynamics (Sept 27, 2001)22 August 1999 Program DYNAMICS generates simulation data for exploring the reach of nonrecursive SEM models in identifying interpretively meaningful system parameters. More specifically, when the endogenous variables in an open system adapt by linear dynamics to initial disequilibrium and exogenous influences, the question to be studied is what conditions on the system and its environment make it possible to recover the system's dynamic parameters from analysis of its variables' synchronic covariances by a suitably constrained SEM model. DYNAMICS allows you to choose structural parameters for a system comprising four variables which influence one another by linear dynamics with some degree of random disturbance. It is intended that two of the four system variables be configured as stable exogenous inputs, but the program allows you to relax that presumption as whimsically as you wish. To run DYNAMICS, first copy DYNAMICS.EXE to a subdirectory that you have created for collecting results from this. (As a test, you can also run it direcly off the floppy.) Then either click on it in Windows or, if in DOS, cd to the appropriate subdirectory and type DYNAMICS at the DOS prompt. The documentation you see on screen should adequately apprise you of what you need to enter and what will result from that. (If not, please complain to me so I can rectify the deficiency.) If you find the output of DYMAMICS useful but would prefer an expansion of its versatility (such as how it randomizes and/or standardizes initial state and disturbances), please advise me of that. This program's source file, DYNAMICS.FOR, is also included here in case you have some acquaintence with Fortran or a similar programming language and are curious about the program's design. Note that just a few lines suffice to execute its computations and data collections; all the source code's heavy breathing is managing the interactive I/O. Wm. W. Rozeboom Department of Psychology University of Alberta E-mail:rozeboom@ualberta.ca P.S. This package also includes, in OUTAUG17.TXT, some correspondence I had at the time of this program's creation regarding its logic.