Add Feature/321 parameter history (#557)

* added parameter history
Closes #557 
Co-authored-by: Jörn Weißenborn <joern.weissenborn@gmail.com>

glotaran/analysis/optimize.py

@@ -41,6 +41,7 @@ def optimize_problem(problem: Problem, verbose: bool = True) -> Result:
     xtol = problem.scheme.xtol
     verbose = 2 if verbose else 0
     termination_reason = ""
+    history_index = -1
 
     try:
         ls_result = least_squares(
@@ -60,10 +61,13 @@ def optimize_problem(problem: Problem, verbose: bool = True) -> Result:
         warn(f"Optimization failed:\n\n{e}")
         termination_reason = str(e)
         ls_result = None
+        history_index = -2
+
+    problem.save_parameters_for_history()
 
     return Result(
         problem.scheme,
-        problem.create_result_data(),
+        problem.create_result_data(history_index=history_index),
         problem.parameters,
         problem.additional_penalty,
         ls_result,
@@ -73,6 +77,7 @@ def optimize_problem(problem: Problem, verbose: bool = True) -> Result:
 
 
 def _calculate_penalty(parameters: np.ndarray, labels: List[str] = None, problem: Problem = None):
+    problem.save_parameters_for_history()
     problem.parameters.set_from_label_and_value_arrays(labels, parameters)
     problem.reset()
     return problem.full_penalty

glotaran/analysis/problem.py

@@ -91,6 +91,7 @@ def __init__(self, scheme: Scheme):
         self._filled_dataset_descriptors = None
 
         self.parameters = scheme.parameters.copy()
+        self._parameter_history = []
 
         # all of the above are always not None
 
@@ -144,6 +145,10 @@ def parameters(self, parameters: ParameterGroup):
         self._parameters = parameters
         self.reset()
 
+    @property
+    def parameter_history(self) -> List[ParameterGroup]:
+        return self._parameter_history
+
     @property
     def grouped(self) -> bool:
         return self._grouped
@@ -255,6 +260,9 @@ def full_penalty(self) -> np.ndarray:
             )
         return self._full_penalty
 
+    def save_parameters_for_history(self):
+        self._parameter_history.append(self._parameters)
+
     def reset(self):
         """Resets all results and `DatasetDescriptors`. Use after updating parameters."""
         self._filled_dataset_descriptors = {
@@ -810,8 +818,12 @@ def calculate_additional_penalty(self) -> Union[np.ndarray, Dict[str, np.ndarray
             self._additional_penalty = None
         return self._additional_penalty
 
-    def create_result_data(self, copy: bool = True) -> Dict[str, xr.Dataset]:
+    def create_result_data(
+        self, copy: bool = True, history_index: int = None
+    ) -> Dict[str, xr.Dataset]:
 
+        if history_index is not None and history_index != -1:
+            self.parameters = self.parameter_history[history_index]
         result_data = {label: self._create_result_dataset(label, copy=copy) for label in self.data}
 
         if callable(self.model.finalize_data):