! This little LINGO program illustrates a general way of
 doing parametric analysis and computing efficient frontiers;
! Keywords: Parametric Analysis, Efficient Frontier;

SUBMODEL parametric:
 ! The Astro/Cosmo product mix model with
  the labor usage of Cosmo as a parameter, Pam;
 MAX = profit;
  profit= 20*astro  + 30*cosmo;
             astro               <= 60;
                         cosmo   <= 50;
             astro + Pam*cosmo   <= 120;
ENDSUBMODEL
CALC: ! Set output level to very terse; @SET( "TERSEO", 2); ! Find profit as a function of the labor usage parameter of Cosmo, for parameter = 1, 1.125..., 3; @WRITE(' Parameter Profit Astro Cosmo', @NEWLINE(1)); Pam = 1; @WHILE( Pam #LE# 3: @SOLVE(parametric); @WRITE( @FORMAT(pam,"8.3f") ,' ', @FORMAT(profit,"8.3f"),' ', @FORMAT(astro,"8.3f"),' ', @FORMAT(cosmo,"8.3f"),@NEWLINE(1)); Pam = Pam + .125; ); ENDCALC ! The above produces the output: Parameter Profit Astro Cosmo 1.000 2700.000 60.000 50.000 1.125 2700.000 60.000 50.000 1.250 2650.000 57.500 50.000 1.375 2525.000 51.250 50.000 1.500 2400.000 45.000 50.000 1.625 2307.692 60.000 36.923 1.750 2228.571 60.000 34.286 1.875 2160.000 60.000 32.000 2.000 2100.000 60.000 30.000 2.125 2047.059 60.000 28.235 2.250 2000.000 60.000 26.667 2.375 1957.895 60.000 25.263 2.500 1920.000 60.000 24.000 2.625 1885.714 60.000 22.857 2.750 1854.545 60.000 21.818 2.875 1826.087 60.000 20.870 3.000 1800.000 60.000 20.000 ;