Faster evaluation for MPM2

[schaepermeier]

This PR adds support for extracting all instance-specific information for MPM2 problems from the original Python environment, and subsequently evaluating the problems within R instead of Python. This behavior is controlled by an additional parameter evaluation.env, which per default is set to the faster R.
It can be significantly faster in multi-objective optimization settings as the Python interface always only stores the configuration of the latest MPM2 function called, leading to expensive reconfigurations for each batch of evaluations.
Even in single-objective settings it is somewhat faster (about 20% for me).

In multi-objective settings it can easily be orders of magnitude faster when the MPM2 instance generation algorithm takes comparatively long to configure the problem. For example, on my machine:

> env = "Python"
> 
> fn1 = makeMPM2Function(16, 2, "random", 8, evaluation.env = env)
> fn2 = makeMPM2Function(16, 2, "random", 9, evaluation.env = env)
> 
> system.time({
+   sapply(1:1e2, function(i) {
+     fn1(c(0.5, 0.5))
+     fn2(c(0.5, 0.5))
+   })
+ })
   user  system elapsed 
  1.239   0.002   0.613 
> library(smoof)
> 
> env = "R"
> 
> fn1 = makeMPM2Function(16, 2, "random", 8, evaluation.env = env)
> fn2 = makeMPM2Function(16, 2, "random", 9, evaluation.env = env)
> 
> system.time({
+   sapply(1:1e2, function(i) {
+     fn1(c(0.5, 0.5))
+     fn2(c(0.5, 0.5))
+   })
+ })
   user  system elapsed 
  0.018   0.000   0.011 
> 

Tests to check matching outputs are also provided. Let me know if you need me to change anything!

Cheers,
Lennart

[jakobbossek]

Looks good!

[jakobbossek]

There are some conflicts with the NEWS files most likely because I just merged your PR on the extended biobj. BBOB suite. Please fix ASAP.

[schaepermeier]

That should fix it :-)

[jakobbossek]

Hmm, the case-sensitivity here is actually not user-friendly. Should we allow arbitrary string? E.g., r or R or pYthon or PyThOn?

[schaepermeier]

Good catch, I made it case-insensitive now

[jakobbossek]

General comment: given your nice contribution I suggest to add yourself to the list of contributors in DESCRIPTION 🥳

[jakobbossek]

Great!

[jakobbossek]

Thanks Lennart for your super-fast responses! Merging 😎