Refactor Manifold.open_subset methods through new method _init_open_s…

…ubset

src/sage/manifolds/differentiable/degenerate_submanifold.py

@@ -12,7 +12,7 @@
 lightlike submanifold) and in General Relativity. In geometry of lightlike
 submanifolds, according to the dimension `r` of the radical distribution
 (see below for definition of radical distribution), degenerate submanifolds
-have been classify into 4 subgroups: `r`-lightlike submanifolds, Coisotropic
+have been classified into 4 subgroups: `r`-lightlike submanifolds, Coisotropic
 submanifolds, Isotropic submanifolds and Totally lightlike submanifolds.
 (See the book of Krishan L. Duggal and Aurel Bejancu [DS2010]_.)
 

src/sage/manifolds/differentiable/differentiable_submanifold.py

@@ -281,29 +281,5 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                          diff_degree=self._diff_degree,
                                          latex_name=latex_name,
                                          start_index=self._sindex)
-        ## Copy of DifferentiableManifold.open_subset. Refactor?
-        resu._calculus_method = self._calculus_method
-        resu._supersets.update(self._supersets)
-        for sd in self._supersets:
-            sd._subsets.add(resu)
-        self._top_subsets.add(resu)
-        # Charts on the result from the coordinate definition:
-        for chart, restrictions in coord_def.items():
-            if chart not in self._atlas:
-                raise ValueError("the {} does not belong to ".format(chart) +
-                                 "the atlas of {}".format(self))
-            chart.restrict(resu, restrictions)
-        # Transition maps on the result inferred from those of self:
-        for chart1 in coord_def:
-            for chart2 in coord_def:
-                if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
-                    self._coord_changes[(chart1, chart2)].restrict(resu)
-        #!# update vector frames and change of frames
-        #
-        ## Extras for Submanifold
-        if self._immersed:
-            resu.set_immersion(self._immersion.restrict(resu),
-                               var=self._var, t_inverse=self._t_inverse)
-        if self._embedded:
-            resu.declare_embedding()
+        self._init_open_subset(resu, coord_def=coord_def)
         return resu

src/sage/manifolds/differentiable/manifold.py

@@ -826,25 +826,13 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                       diff_degree=self._diff_degree,
                                       latex_name=latex_name,
                                       start_index=self._sindex)
-        resu._calculus_method = self._calculus_method
-        resu._supersets.update(self._supersets)
-        for sd in self._supersets:
-            sd._subsets.add(resu)
-        self._top_subsets.add(resu)
-        # Charts on the result from the coordinate definition:
-        for chart, restrictions in coord_def.items():
-            if chart not in self._atlas:
-                raise ValueError("the {} does not belong to ".format(chart) +
-                                 "the atlas of {}".format(self))
-            chart.restrict(resu, restrictions)
-        # Transition maps on the result inferred from those of self:
-        for chart1 in coord_def:
-            for chart2 in coord_def:
-                if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
-                    self._coord_changes[(chart1, chart2)].restrict(resu)
-        #!# update vector frames and change of frames
+        self._init_open_subset(resu, coord_def=coord_def)
         return resu
 
+    def _init_open_subset(self, resu, coord_def):
+        super()._init_open_subset(resu, coord_def=coord_def)
+        #!# update vector frames and change of frames
+
     def diff_map(self, codomain, coord_functions=None, chart1=None,
                        chart2=None, name=None, latex_name=None):
         r"""

src/sage/manifolds/differentiable/pseudo_riemannian.py

@@ -745,22 +745,5 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                         latex_name=latex_name,
                                         metric_latex_name=self._metric_latex_name,
                                         start_index=self._sindex)
-        resu._calculus_method = self._calculus_method
-        resu._supersets.update(self._supersets)
-        for sd in self._supersets:
-            sd._subsets.add(resu)
-        self._top_subsets.add(resu)
-        # Charts on the result from the coordinate definition:
-        for chart, restrictions in coord_def.items():
-            if chart not in self._atlas:
-                raise ValueError("the {} does not belong to ".format(chart) +
-                                 "the atlas of {}".format(self))
-            chart.restrict(resu, restrictions)
-        # Transition maps on the result inferred from those of self:
-        for chart1 in coord_def:
-            for chart2 in coord_def:
-                if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
-                    self._coord_changes[(chart1, chart2)].restrict(resu)
-        #!# update non-coordinate vector frames and change of frames
-        #
+        self._init_open_subset(resu, coord_def=coord_def)
         return resu

src/sage/manifolds/differentiable/pseudo_riemannian_submanifold.py

@@ -460,31 +460,7 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                            latex_name=latex_name,
                                            metric_latex_name=self._metric_latex_name,
                                            start_index=self._sindex)
-        ## Copy of PseudoRiemannianManifold.open_subset. Refactor?
-        resu._calculus_method = self._calculus_method
-        resu._supersets.update(self._supersets)
-        for sd in self._supersets:
-            sd._subsets.add(resu)
-        self._top_subsets.add(resu)
-        # Charts on the result from the coordinate definition:
-        for chart, restrictions in coord_def.items():
-            if chart not in self._atlas:
-                raise ValueError("the {} does not belong to ".format(chart) +
-                                 "the atlas of {}".format(self))
-            chart.restrict(resu, restrictions)
-        # Transition maps on the result inferred from those of self:
-        for chart1 in coord_def:
-            for chart2 in coord_def:
-                if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
-                    self._coord_changes[(chart1, chart2)].restrict(resu)
-        #!# update non-coordinate vector frames and change of frames
-        #
-        ## Extras for Submanifold
-        if self._immersed:
-            resu.set_immersion(self._immersion.restrict(resu),
-                               var=self._var, t_inverse=self._t_inverse)
-        if self._embedded:
-            resu.declare_embedding()
+        self._init_open_subset(resu, coord_def=coord_def)
         return resu
 
     def ambient_metric(self):

src/sage/manifolds/manifold.py

@@ -872,6 +872,10 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                    base_manifold=self._manifold,
                                    latex_name=latex_name,
                                    start_index=self._sindex)
+        self._init_open_subset(resu, coord_def=coord_def)
+        return resu
+
+    def _init_open_subset(self, resu, coord_def):
         resu._calculus_method = self._calculus_method
         resu._supersets.update(self._supersets)
         for sd in self._supersets:
@@ -888,7 +892,6 @@ def open_subset(self, name, latex_name=None, coord_def={}):
             for chart2 in coord_def:
                 if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
                     self._coord_changes[(chart1, chart2)].restrict(resu)
-        return resu
 
     def get_chart(self, coordinates, domain=None):
         r"""

src/sage/manifolds/topological_submanifold.py

@@ -317,30 +317,17 @@ def open_subset(self, name, latex_name=None, coord_def={}):
                                       base_manifold=self._manifold,
                                       latex_name=latex_name,
                                       start_index=self._sindex)
-        ## Copy of TopologicalManifold.open_subset. Refactor?
-        resu._calculus_method = self._calculus_method
-        resu._supersets.update(self._supersets)
-        for sd in self._supersets:
-            sd._subsets.add(resu)
-        self._top_subsets.add(resu)
-        # Charts on the result from the coordinate definition:
-        for chart, restrictions in coord_def.items():
-            if chart not in self._atlas:
-                raise ValueError("the {} does not belong to ".format(chart) +
-                                 "the atlas of {}".format(self))
-            chart.restrict(resu, restrictions)
-        # Transition maps on the result inferred from those of self:
-        for chart1 in coord_def:
-            for chart2 in coord_def:
-                if chart2 != chart1 and (chart1, chart2) in self._coord_changes:
-                    self._coord_changes[(chart1, chart2)].restrict(resu)
+        self._init_open_subset(resu, coord_def=coord_def)
+        return resu
+
+    def _init_open_subset(self, resu, coord_def):
+        super()._init_open_subset(resu, coord_def=coord_def)
         ## Extras for Submanifold
         if self._immersed:
             resu.set_immersion(self._immersion.restrict(resu),
                                var=self._var, t_inverse=self._t_inverse)
         if self._embedded:
             resu.declare_embedding()
-        return resu
 
     def set_immersion(self, phi, inverse=None, var=None,
                       t_inverse=None):