/*
** NLLS.SIM
** (C) Copyright 1988-1993 by Aptech Systems, Inc.
** All Rights Reserved.
**
**   This command file generates a data set for OPT*.E
**   and MAX6.E.  The model is:
**
**      Y = C0 + C1*EXP(-C3*T)
**
*/

cls;
print "NLLS.SIM - nonlinear equation simulation program";
print;
print "model:  y = c[1] * exp(-c[3]*t)";
print;
print "  How large a sample do you want to use";;
nobs = con(1,1);
print;


@ -- coefficients -- @
c = { 0.8, .2 };

seed = 77635567;

t = seqa(0,1,nobs);

e = rndns(nobs,1,seed);      @ prediction error @

y = c[1] * exp(-c[2]*t) + .7*e;

z = y~t;

if saved(z,"NLLS","Y"|"T");
  print ("file NLLS.DAT created");
else;
  print "attempt to save file failed";
endif;
end;