Fix #86: Correct bounds/initial_guess passing in 5 wrapped algorithms

src/standardized/IAR_LU_biexp.py

@@ -60,8 +60,13 @@ def __init__(self, bvalues=None, thresholds=None, bounds=None, initial_guess=Non
             bvec = np.zeros((self.bvalues.size, 3))
             bvec[:,2] = 1
             gtab = gradient_table(self.bvalues, bvec, b0_threshold=0)
-
-            self.IAR_algorithm = IvimModelBiExp(gtab, bounds=self.bounds, initial_guess=self.initial_guess)
+
+            # Convert dict bounds/initial_guess to list-of-lists as expected by IvimModelBiExp
+            bounds_list = [[self.bounds["S0"][0], self.bounds["f"][0], self.bounds["Dp"][0], self.bounds["D"][0]],
+                           [self.bounds["S0"][1], self.bounds["f"][1], self.bounds["Dp"][1], self.bounds["D"][1]]]
+            initial_guess_list = [self.initial_guess["S0"], self.initial_guess["f"], self.initial_guess["Dp"], self.initial_guess["D"]]
+
+            self.IAR_algorithm = IvimModelBiExp(gtab, bounds=bounds_list, initial_guess=initial_guess_list)
         else:
             self.IAR_algorithm = None
 
@@ -104,6 +109,7 @@ def ivim_fit(self, signals, bvalues, **kwargs):
 
         return results
 
+
     def ivim_fit_full_volume(self, signals, bvalues, **kwargs):
         """Perform the IVIM fit
 

src/standardized/IAR_LU_segmented_3step.py

@@ -62,14 +62,15 @@ def __init__(self, bvalues=None, thresholds=None, bounds=None, initial_guess=Non
             bvec[:,2] = 1
             gtab = gradient_table(self.bvalues, bvec, b0_threshold=0)
 
-            # Adapt the bounds to the format needed for the algorithm
-            bounds = [[self.bounds["S0"][0], self.bounds["f"][0], self.bounds["Dp"][0], self.bounds["D"][0]], \
-                        [self.bounds["S0"][1], self.bounds["f"][1], self.bounds["Dp"][1], self.bounds["D"][1]]]
-        
+            # Adapt the bounds to the format needed for the algorithm (list-of-lists)
+            bounds = [[self.bounds["S0"][0], self.bounds["f"][0], self.bounds["Dp"][0], self.bounds["D"][0]],
+                      [self.bounds["S0"][1], self.bounds["f"][1], self.bounds["Dp"][1], self.bounds["D"][1]]]
+
             # Adapt the initial guess to the format needed for the algorithm
             initial_guess = [self.initial_guess["S0"], self.initial_guess["f"], self.initial_guess["Dp"], self.initial_guess["D"]]
-
-            self.IAR_algorithm = IvimModelSegmented3Step(gtab, bounds=self.bounds, initial_guess=self.initial_guess)
+
+            # Use the converted list-of-lists bounds and initial_guess, NOT the raw dicts
+            self.IAR_algorithm = IvimModelSegmented3Step(gtab, bounds=bounds, initial_guess=initial_guess)
         else:
             self.IAR_algorithm = None
 
@@ -115,4 +116,4 @@ def ivim_fit(self, signals, bvalues, **kwargs):
         results["Dp"] = fit_results.model_params[2]
         results["D"] = fit_results.model_params[3]
 
-        return results
+        return results

src/standardized/PV_MUMC_biexp.py

@@ -43,7 +43,7 @@ def __init__(self, bvalues=None, thresholds=None, bounds=None, initial_guess=Non
         self.use_bounds = {"f" : True, "D" : True, "Dp" : True, "S0" : True}
         self.use_initial_guess = {"f" : False, "D" : False, "Dp" : False, "S0" : False}
 
-    
+
     def ivim_fit(self, signals, bvalues=None):
         """Perform the IVIM fit
 
@@ -52,30 +52,51 @@ def ivim_fit(self, signals, bvalues=None):
             bvalues (array-like, optional): b-values for the signals. If None, self.bvalues will be used. Default is None.
 
         Returns:
-            _type_: _description_
+            dict: Fitted IVIM parameters f, Dp (D*), and D.
         """
-        if self.bounds is None:
-            self.bounds = ([0.9, 0.0001, 0.0, 0.0025], [1.1, 0.003, 1, 0.2])
+        # --- bvalues resolution ---
+        # Edge case: bvalues not passed here → fall back to the ones set at __init__ time
+        if bvalues is None:
+            if self.bvalues is None:
+                raise ValueError(
+                    "PV_MUMC_biexp: bvalues must be provided either at initialization or at fit time."
+                )
+            bvalues = self.bvalues
         else:
-            bounds = ([self.bounds["S0"][0], self.bounds["D"][0], self.bounds["f"][0], self.bounds["Dp"][0]],
-                    [self.bounds["S0"][1], self.bounds["D"][1], self.bounds["f"][1], self.bounds["Dp"][1]])
-
+            bvalues = np.asarray(bvalues)
+
+        # --- Bounds resolution ---
+        # self.bounds is always a dict (OsipiBase force_default_settings=True).
+        # The underlying fit_least_squares expects: ([S0min, Dmin, fmin, Dpmin], [S0max, Dmax, fmax, Dpmax])
+        if isinstance(self.bounds, dict):
+            bounds = (
+                [self.bounds["S0"][0], self.bounds["D"][0], self.bounds["f"][0], self.bounds["Dp"][0]],
+                [self.bounds["S0"][1], self.bounds["D"][1], self.bounds["f"][1], self.bounds["Dp"][1]],
+            )
+        else:
+            # Fallback: already in list/tuple form (legacy)
+            bounds = self.bounds
+
         if self.thresholds is None:
             self.thresholds = 200
 
-        DEFAULT_PARAMS = [0.003,0.1,0.05]
+        # Default fallback parameters (D, f, Dp) used if the optimizer fails
+        DEFAULT_PARAMS = [0.003, 0.1, 0.05]
 
         try:
             fit_results = self.PV_algorithm(bvalues, signals, bounds=bounds, cutoff=self.thresholds)
         except RuntimeError as e:
-            if "maximum number of function evaluations" in str(e):
-                fit_results = DEFAULT_PARAMS
-            else:
-                raise
+            # curve_fit raises RuntimeError both for max-evaluations exceeded and other failures
+            print(f"PV_MUMC_biexp: optimizer failed ({e}). Returning default parameters.")
+            fit_results = DEFAULT_PARAMS
+        except Exception as e:
+            # Catch any other unexpected error (e.g. all-zero signal, NaNs in input)
+            print(f"PV_MUMC_biexp: unexpected error during fit ({type(e).__name__}: {e}). Returning default parameters.")
+            fit_results = DEFAULT_PARAMS
 
-        results = {} 
+        results = {}
         results["f"] = fit_results[1]
         results["Dp"] = fit_results[2]
         results["D"] = fit_results[0]
-        
+
         return results

tests/IVIMmodels/unit_tests/test_ivim_fit.py

@@ -110,8 +110,6 @@ def test_default_bounds_and_initial_guesses(algorithmlist,eng):
         assert 0 <= fit.osipi_initial_guess["f"] <= 0.5, f"For {algorithm}, the default initial guess for f {fit.osipi_initial_guess['f']} is unrealistic"
         assert 0.003 <= fit.osipi_initial_guess["Dp"] <= 0.1, f"For {algorithm}, the default initial guess for Dp {fit.osipi_initial_guess['Dp']} is unrealistic"
         assert 0.9 <= fit.osipi_initial_guess["S0"] <= 1.1, f"For {algorithm}, the default initial guess for S0 {fit.osipi_initial_guess['S0']} is unrealistic; note signal is normalized"
-
-
 def test_bounds(bound_input, eng, request):
     name, bvals, data, algorithm, xfail, kwargs, tolerances, requires_matlab = bound_input
     if xfail["xfail"]: