Specify unified output of the optimization run.

[PavelBal]

Currently, the output of an optimization run

piResults <- piTask$run()

depends on the algorithm used. We should create our own output format (named list?) and populate it internally depending on the used algo, so that it always contains the same information. Also brainstorm on the user friendly structure, the current output is not that convenient:

> print(piResults)
$par
[1] -1.2816387  0.8352532  0.7571563

$value
[1] 6.536445

$iter
[1] 109

$convergence
[1] 1

$message
[1] "NLOPT_SUCCESS: Generic success return value."

$elapsed
[1] 34.06

$algorithm
[1] "BOBYQA"

$nrOfFnEvaluations
[1] 111

$hessian
          [,1]          [,2]          [,3]
[1,] 49.859194 -4.596684e+00 -5.102561e+00
[2,] -4.596684  2.127266e+01  1.193018e-11
[3,] -5.102561  1.193018e-11  2.534869e+01

$sigma
[1] 0.2044678 0.3097894 0.2838900

$lwr
[1] -1.6823882  0.2280772  0.2007420

$upr
[1] -0.8808893  1.4424293  1.3135706

$cv
[1] 15.95362 37.08928 37.49425

[PavelBal]

And document then in the vignette.