Introduce Chars

This improves the implementation by introducing a class to manage the characters

src/ilp_keyboard_layout_optimization/ilp.py

@@ -2,16 +2,6 @@
 from itertools import chain, permutations, product
 from typing import Iterable
 
-from .type_aliases import (
-    CharKeyPair,
-    CharKeyQuadruple,
-    CharTuple,
-    KeyTuple,
-    LinCosts,
-    LinVars,
-    QuadCosts,
-    QuadVars,
-)
 from pyscipopt import Model, quicksum
 
 from .data_aquisition.chars import Chars
@@ -30,52 +20,52 @@ class KeyboardOptimization:
     """Instances of this class represent instances of the keyboard layout QAP
 
     The IP variant of an optimization of character to key assignments can be modeled
-    as a so called quadratic assignment problem (QAP). The task is to assign a set of
+    as a so-called quadratic assignment problem (QAP). The task is to assign a set of
     characters to a set of keys on a keyboard. The way in which they should be
     arranged has to meet certain criteria such as for instance: characters that are
-    often typed after one another should not be assigned to keys, that are supposed
+    often typed after one another should not be assigned to positions, that are supposed
     to be pressed by the same finger.
 
     Parameters
     ----------
     chars : CharTuple
         the (special) characters to be assign
-    keys: KeyTuple
-        the keys to which we want to assign the (special) characters
+    poss: PosTuple
+        the positions to which we want to assign the (special) characters
     """
 
-    chars: CharTuple
-    keys: KeyTuple
+    chars: Chars
+    poss: PosTuple
 
     def __init__(self, chars: Chars, poss: PosTuple):
         assert len(chars.monos) == len(poss)
         self.chars = chars
-        self.keys = keys
-        self.char_key_assigns: LinVars = {}
-        self.quad_char_key_assigns: QuadVars = {}
-        self.char_key_costs: LinCosts = {}
-        self.quad_char_key_costs: QuadCosts = {}
+        self.poss = poss
+        self.char_pos_assigns: LinVars = {}
+        self.quad_char_pos_assigns: QuadVars = {}
+        self.char_pos_costs: LinCosts = {}
+        self.quad_char_pos_costs: QuadCosts = {}
         self.model: Model = Model("Keyboard Layout Optimization")
 
     def set_up_model(self, char_key_costs: LinCosts, quad_char_key_costs: QuadCosts):
         """Set up all the variables and initialize the costs for the SCIP model"""
         for (char, key) in self.char_key_assigns_keys:
-            self.char_key_assigns[char, key] = self.model.addVar(
+            self.char_pos_assigns[char, key] = self.model.addVar(
                 name=f"{key}={char}", vtype="B"
             )
         for (char, char_2, key, key_2) in self.quad_char_key_assigns_keys:
-            self.quad_char_key_assigns[char, char_2, key, key_2] = self.model.addVar(
+            self.quad_char_pos_assigns[char, char_2, key, key_2] = self.model.addVar(
                 name=f"{key}={char}_and_{key_2}={char_2}", vtype="C", lb=0, ub=1
             )
-        assert len(quad_char_key_costs) == len(self.quad_char_key_assigns)
-        assert len(char_key_costs) == len(self.char_key_assigns)
-        self.char_key_costs = char_key_costs
-        self.quad_char_key_costs = quad_char_key_costs
+        assert len(quad_char_key_costs) == len(self.quad_char_pos_assigns)
+        assert len(char_key_costs) == len(self.char_pos_assigns)
+        self.char_pos_costs = char_key_costs
+        self.quad_char_pos_costs = quad_char_key_costs
 
         constr = {}
         for char in self.chars.monos:
             self.model.addCons(
-                quicksum(self.char_key_assigns[char, key] for key in self.keys) == 1,
+                quicksum(self.char_pos_assigns[char, key] for key in self.poss) == 1,
                 f"AllCharacterAssignedOnce({char})",
             )
             for (key, key_2) in self.key_pairs:
@@ -85,7 +75,7 @@ class KeyboardOptimization:
                         for char_2 in self.chars.monos
                         if char_2 != char
                     )
-                    <= self.char_key_assigns[char, key],
+                    <= self.char_pos_assigns[char, key],
                     f"QuadCharacterAssignedLEQThanPosition({char},{key},{key_2})",
                 )
                 self.model.addCons(
@@ -94,7 +84,7 @@ class KeyboardOptimization:
                         for char_2 in self.chars.monos
                         if char_2 != char
                     )
-                    <= self.char_key_assigns[char, key],
+                    <= self.char_pos_assigns[char, key],
                     f"QuadCharacterAssignedLEQThanSecondPosition({char},{key_2},{key})",
                 )
             for char_2 in self.chars.monos:
@@ -102,35 +92,36 @@ class KeyboardOptimization:
                     if char_2 != char:
                         self.model.addCons(
                             quicksum(
-                                self.quad_char_key_assigns[char, char_2, key, key_2]
-                                for key_2 in self.keys
+                                self.quad_char_pos_assigns[char, char_2, key, key_2]
+                                for key_2 in self.poss
                                 if key_2 != key
                             )
-                            <= self.char_key_assigns[char, key],
+                            <= self.char_pos_assigns[char, key],
                             f"QuadCharacterAssignedLEQThanCharacter({char},{char_2},"
                             f"{key})",
                         )
                         self.model.addCons(
                             quicksum(
-                                self.quad_char_key_assigns[char_2, char, key_2, key]
-                                for key_2 in self.keys
+                                self.quad_char_pos_assigns[char_2, char, key_2, key]
+                                for key_2 in self.poss
                                 if key_2 != key
                             )
-                            <= self.char_key_assigns[char, key],
+                            <= self.char_pos_assigns[char, key],
                             f"QuadCharacterAssignedLEQThanSecondCharacter({char_2},"
                             f"{char},{key})",
                         )
 
         for (char, char_2, key, key_2) in self.quad_char_key_assigns_keys:
             self.model.addCons(
-                self.char_key_assigns[char, key] + self.char_key_assigns[char_2, key_2]
-                <= 1 + self.quad_char_key_assigns[char, char_2, key, key_2],
+                self.char_pos_assigns[char, key] + self.char_pos_assigns[char_2, key_2]
+                <= 1 + self.quad_char_pos_assigns[char, char_2, key, key_2],
                 f"IntegrableQuadAssign({char},{key_2},{key})",
             )
 
-        for key in self.keys:
+        for key in self.poss:
             constr[key] = self.model.addCons(
-                quicksum(self.char_key_assigns[char, key] for char in self.chars) == 1,
+                quicksum(self.char_pos_assigns[char, key] for char in self.chars.monos)
+                == 1,
                 f"AllPositionsAssignedOnce({key})",
             )
 
@@ -138,14 +129,14 @@ class KeyboardOptimization:
             quicksum(
                 costs * assigns
                 for (costs, assigns) in zip(
-                    self.char_key_costs.values(), self.char_key_assigns.values()
+                    self.char_pos_costs.values(), self.char_pos_assigns.values()
                 )
             )
             + quicksum(
                 costs * assigns
                 for (costs, assigns) in zip(
-                    self.quad_char_key_costs.values(),
-                    self.quad_char_key_assigns.values(),
+                    self.quad_char_pos_costs.values(),
+                    self.quad_char_pos_assigns.values(),
                 )
             ),
             "minimize",
@@ -169,10 +160,10 @@ class KeyboardOptimization:
         for (char, key) in self.char_key_assigns_keys:
             print(
                 f"({char}, {key}): "
-                f"{self.model.getVal(self.char_key_assigns[char, key])}, "
-                f"cost: {self.char_key_costs[char, key]}"
+                f"{self.model.getVal(self.char_pos_assigns[char, key])}, "
+                f"cost: {self.char_pos_costs[char, key]}"
             )
-            if self.model.getVal(self.char_key_assigns[char, key]) == 1:
+            if self.model.getVal(self.char_pos_assigns[char, key]) == 1:
                 solution_assignments.append((char, key))
 
         assert "('u', 'left_pinky_home')" in str(solution_assignments)
@@ -192,7 +183,7 @@ class KeyboardOptimization:
     @property
     def char_key_assigns_keys(self) -> Iterable[CharPosPair]:
         """An iterator for the pairs of (special) characters and corresponding keys"""
-        return product(self.chars, self.keys)
+        return product(self.chars.monos, self.poss)
 
     @property
     def quad_char_key_assigns_keys(self) -> Iterable[CharPosQuadruple]:
@@ -208,4 +199,4 @@ class KeyboardOptimization:
     @property
     def key_pairs(self) -> Iterable:
         """An iterator for all pairs of keys that are possible"""
-        return permutations(self.keys, 2)
+        return permutations(self.poss, 2)