```r
# five spatially disjoint partitions
tune_level = makeResampleDesc("SpCV", iters = 5)
# use 50 randomly selected hyperparameters
ctrl = makeTuneControlRandom(maxit = 50)
# define the outer limits of the randomly selected hyperparameters
ps = makeParamSet(
  makeNumericParam("C", lower = -12, upper = 15, trafo = function(x) 2^x),
  makeNumericParam("sigma", lower = -15, upper = 6, trafo = function(x) 2^x)
  )
```