Remove use of set() to get knots from knotvector

src/compmec/nurbs/heavy.py

@@ -15,6 +15,18 @@
 
 
 class ImmutableKnotVector(tuple):
+    @staticmethod
+    def __get_unique(vector: Tuple[float]):
+        unique = []
+        for node in vector:
+            for knot in unique:
+                if abs(node - knot) < 1e-6:
+                    break
+            else:
+                unique.append(node)
+        unique.sort()
+        return tuple(unique)
+
     @staticmethod
     def __is_valid(vector: Tuple[float], degree: Union[int, None]):
         try:
@@ -35,7 +47,7 @@ def __is_valid(vector: Tuple[float], degree: Union[int, None]):
         npts = lenght - degree - 1
         if not degree < npts:
             return False
-        knots = tuple(set(vector[degree : npts + 1]))
+        knots = ImmutableKnotVector.__get_unique(vector[degree : npts + 1])
         for knot in knots:
             mult = vector.count(knot)
             if mult > degree + 1:
@@ -75,7 +87,8 @@ def __or__(self, other: ImmutableKnotVector) -> ImmutableKnotVector:
         other = ImmutableKnotVector(other)
         if self.limits != other.limits:
             raise ValueError
-        all_knots = list(set(self.knots) | set(other.knots))
+        all_knots = list(self.knots) + list(other.knots)
+        all_knots = ImmutableKnotVector.__get_unique(all_knots)
         all_mults = [0] * len(all_knots)
         for vector in [self, other]:
             for knot in vector:
@@ -118,7 +131,8 @@ def npts(self) -> int:
 
     @property
     def knots(self) -> Tuple[float]:
-        return tuple(sorted(set(self[self.degree : self.npts + 1])))
+        vector = self[self.degree : self.npts + 1]
+        return ImmutableKnotVector.__get_unique(vector)
 
     @property
     def limits(self) -> Tuple[float]:

src/compmec/nurbs/knotspace.py

@@ -39,6 +39,13 @@ def __new__(cls, vector: Tuple[float], degree: Optional[int] = None):
         instance.internal = vector
         return instance
 
+    def __str__(self) -> str:
+        return "(" + ", ".join(map(str, self)) + ")"
+
+    def __repr__(self) -> str:
+        return str(self)
+        return f"KV({self.degree}, {self.npts})"
+
     def __iter__(self):
         for item in self.internal:
             yield item

tests/test_customstruc.py

@@ -25,7 +25,7 @@ def __init__(self, number: float):
         self.internal = float(number)
 
     def __hash__(self):
-        return hash(self.internal)
+        return id(self)
 
     def __str__(self) -> str:
         return str(self.internal)
@@ -95,6 +95,9 @@ def __ne__(self, other):
     def __ge__(self, other):
         return self.__eq__(other) or self.__gt__(other)
 
+    def __abs__(self):
+        return self.__class__(self.internal if self.internal > 0 else -self.internal)
+
 
 class CustomPoint:
     def __init__(self, value: float):