add comments for my understanding

src/gui_qt/main/management.py

@@ -503,11 +503,25 @@ class UpperManagement(QtCore.QObject):
                         we = we_option
 
                     if m_complex is None or m_complex == 1:
+                        # model is not complex: m_complex = None
+                        # model is complex, fit real part: m_complex = 1
                         _y = data_i.y.real
-                    elif m_complex == 2 and np.iscomplexobj(data_i.y):
-                        _y = data_i.y.imag
+                        data_complex = 1
+                    elif m_complex == 2:
+                        # model is complex, fit imag part: m_complex = 2
+                        if np.iscomplexobj(data_i.y):
+                            # data is complex, use imag part
+                            _y = data_i.y.imag
+                            data_complex = 2
+                        else:
+                            # data is real
+                            _y = data_i.y
+                            data_complex = 1
                     else:
+                        # model is complex, fit complex: m_complex = 0
+                        # use data as given (complex or not)
                         _y = data_i.y
+                        data_complex = 0
 
                     _x = data_i.x
 
@@ -521,9 +535,9 @@ class UpperManagement(QtCore.QObject):
 
                     try:
                         if isinstance(we, str):
-                            d = fit_d.Data(_x[inside], _y[inside], we=we, idx=set_id)
+                            d = fit_d.Data(_x[inside], _y[inside], we=we, idx=set_id, complex_type=data_complex)
                         else:
-                            d = fit_d.Data(_x[inside], _y[inside], we=we[inside], idx=set_id)
+                            d = fit_d.Data(_x[inside], _y[inside], we=we[inside], idx=set_id, complex_type=data_complex)
                     except Exception as e:
                         raise Exception(f'Setting data failed for {set_id}')
 

src/nmreval/fit/data.py

@@ -6,8 +6,8 @@ from .model import Model
 from .parameter import Parameters, Parameter
 
 
-class Data(object):
-    def __init__(self, x, y, we=None, idx=None):
+class Data:
+    def __init__(self, x, y, we=None, idx=None, complex_type: int = 0):
         self.x = np.asarray(x)
         self.y = np.asarray(y)
         if self.y.shape[0] != self.x.shape[0]:
@@ -20,6 +20,7 @@ class Data(object):
         self.parameter = Parameters()
         self.para_keys: list = []
         self.fun_kwargs = {}
+        self.complex_type = complex_type
 
     def __len__(self):
         return self.y.shape[0]

src/nmreval/fit/result.py

@@ -54,6 +54,7 @@ class FitResultCreator:
             nvar: int,
             corr:  np.ndarray,
             pcorr: np.ndarray,
+            data_mode: int = 1,
     ) -> FitResult:
         if np.all(x_orig > 0) and (np.max(x_orig) > 100 * np.min(x_orig)):
             islog = True
@@ -87,9 +88,12 @@ class FitResultCreator:
 
         if not actual_mode < 0:
             if actual_mode == 1:
-                _y.imag = 0
+                _Y = _y.real
+                # _y.imag = 0
             elif actual_mode == 2:
-                _y.real = 0
+                # if data_mode ==
+                _y = _y.imag
+                # _y.real = 0
 
             fun_kwargs['complex_mode'] = actual_mode