Update climada/util/calibrate/bayesian_optimizer.py

Use negative cost function as target function in BayesianOptimizer

Co-authored-by: Thomas Vogt <[email protected]>

Author: peanutfun

climada/util/calibrate/bayesian_optimizer.py

@@ -86,7 +86,7 @@ def __post_init__(
 
     def _target_func(self, impact: Impact, data: pd.DataFrame) -> Number:
         """Invert the cost function because BayesianOptimization maximizes the target"""
-        return 1 / self.input.cost_func(impact, data)
+        return -self.input.cost_func(impact, data)
 
     def run(self, **opt_kwargs):
         """Execute the optimization