effective epsilon-constraint:

G. Mavrotas introduced an improvement of epsilon-constraint method using lexicographic optimization for the payoff table. The new method is called AUGMECON and is included in gams libray.

see other improvement

2 manners to get "The time of execution" in gams.

1. Using function:  timeExec

see Manual 

2. Using function: jnow

startTime = jnow;
...
elapsedTime = (jnow - startTime)*24*3600;

see wiki

Sorting as LP

http://cs.stackexchange.com/questions/4805/sorting-as-a-linear-program

Dibujar una superficie con R:

Este el código que hace esto:

require(grDevices) # for trans3d
## More examples in  demo(persp) !!
##                   -----------

# (1) The Obligatory Mathematical surface.
#     Rotated sinc function.

x <- 5="" length="30)<br" seq="">y <- br="" x="">f <- br="" function="" r="" x="" y="">z <- br="" f="" outer="" x="" y="">z[is.na(z)] <- 1="" br="">op <- bg="white" br="" par="">persp(x, y, z, theta = 30, phi = 30, expand = 0.5, col = "lightblue");