`b_asic.quantization`¶

B-ASIC quantization module.

class b_asic.quantization.OverflowMode(value)¶

Overflow types.

SATURATION = 2¶

Two’s complement saturation.

Overflow return the most positive/negative number.

WRAPPING = 1¶: Two’s complement overflow, i.e., remove the more significant bits.

to_apytypes() → OverflowMode¶

Convert to APyTypes OverflowMode.

Returns:

ApyOverflowMode: The corresponding APyTypes overflow mode.

class b_asic.quantization.QuantizationMode(value)¶

Quantization types.

JAMMING = 4¶: Jamming/von Neumann rounding, i.e., set the LSB to one.

MAGNITUDE_TRUNCATION = 3¶: Magnitude truncation, i.e., round towards zero.

ROUNDING = 1¶: Standard two’s complement rounding, i.e, tie rounds towards infinity.

TRUNCATION = 2¶: Two’s complement truncation, i.e., round towards negative infinity.

UNBIASED_JAMMING = 6¶: Unbiased jamming/von Neumann rounding.

UNBIASED_ROUNDING = 5¶: Unbiased rounding, i.e., tie rounds towards even.

to_apytypes() → QuantizationMode¶

Convert to APyTypes QuantizationMode.

Returns:

ApyQuantizationMode: The corresponding APyTypes quantization mode.

Raises:

ValueError: If the mode has no APyTypes equivalent.

Quantize value assuming two’s complement representation.

Quantization happens before overflow, so, e.g., rounding may lead to an overflow.

The total number of bits is fractional_bits + integer_bits. However, there is no check that this will be a positive number. Note that the sign bit is included in these bits. If integer_bits is not given, then use 1, i.e., the result is between

\[-1 \leq \text{value} \leq 1-2^{-\text{fractional_bits}}\]

If value is a complex number, the real and imaginary parts are quantized separately.

Parameters:

valueint, float, complex: The value to be quantized.
fractional_bitsint: Number of fractional bits, can be negative.
integer_bitsint, default: 1: Number of integer bits, can be negative.
quantization_modeQuantizationMode, default: QuantizationMode.TRUNCATION: Type of quantization to use.
overflow_modeOverflowMode, default: OverflowMode.WRAPPING: Type of overflow to use.

Returns:

int, float, complex: The quantized value.

Examples

>>> from b_asic.quantization import quantize, QuantizationMode, OverflowMode
...
... quantize(0.3, 4)  # Truncate 0.3 using four fractional bits and one integer bit
0.25
>>> quantize(0.3, 4, quantization_mode=QuantizationMode.ROUNDING)  # As above, but round
0.3125
>>> quantize(1.3, 4)  # Will overflow
-0.75
>>> quantize(1.3, 4, 2)  # Use two integer bits
1.25
>>> quantize(1.3, 4, overflow_mode=OverflowMode.SATURATION)  # use saturation
0.9375
>>> quantize(0.3, 4, -1)  # Three bits in total, will overflow
-0.25

b_asic.quantization¶

`b_asic.quantization`¶