Add quantize function and enums

Closes #194 (closed)

b_asic/quantization.py

+"""B-ASIC quantization module."""
+
+import math
+from enum import Enum
+
+from b_asic.types import Num
+
+
+class Quantization(Enum):
+    """Quantization tyoes."""
+
+    ROUNDING = 1
+    TRUNCATION = 2
+    MAGNITUDE_TRUNCATION = 3
+    JAMMING = 4
+
+
+class Overflow(Enum):
+    """Overflow types."""
+
+    TWOS_COMPLEMENT = 1
+    SATURATION = 2
+
+
+def quantize(
+    value: Num,
+    fractional_bits: int,
+    integer_bits: int = 1,
+    quantization: Quantization = Quantization.TRUNCATION,
+    overflow: Overflow = Overflow.TWOS_COMPLEMENT,
+):
+    """
+    Quantize *value*.
+
+    Parameters
+    ----------
+    value : int, float, complex
+    fractional_bits : int
+    integer_bits : int, default: 1
+    quantization : Quantization, default: Quantization.TRUNCATION
+    overflow : Overflow, default: Overflow.SATURATION
+
+    Returns
+    -------
+
+
+    """
+    if isinstance(value, complex):
+        return complex(
+            quantize(
+                value.real,
+                fractional_bits=fractional_bits,
+                integer_bits=integer_bits,
+                quantization=quantization,
+                overflow=overflow,
+            ),
+            quantize(
+                value.imag,
+                fractional_bits=fractional_bits,
+                integer_bits=integer_bits,
+                quantization=quantization,
+                overflow=overflow,
+            ),
+        )
+    b = 2**fractional_bits
+    v = b * value
+    if quantization is Quantization.TRUNCATION:
+        v = math.floor(v)
+    elif quantization is Quantization.ROUNDING:
+        v = math.floor(v + 0.5)
+    elif quantization is Quantization.MAGNITUDE_TRUNCATION:
+        if v >= 0:
+            v = math.floor(v)
+        else:
+            v = math.ceil(v)
+    else:  # Quantization.JAMMING
+        v = math.floor(v) | 1
+
+    # TODO: overflow handling
+
+    return v / b