feat: add quantization utilities

tests/quantization/test_quantized_array.py

@@ -0,0 +1,53 @@
+"""Tests for the quantized array/tensors."""
+import numpy
+import pytest
+
+from concrete.quantization import QuantizedArray
+
+N_BITS_ATOL_TUPLE_LIST = [
+    (32, 10 ** -2),
+    (28, 10 ** -2),
+    (20, 10 ** -2),
+    (16, 10 ** -1),
+    (8, 10 ** -0),
+    (4, 10 ** -0),
+]
+
+
+@pytest.mark.parametrize(
+    "n_bits, atol",
+    [pytest.param(n_bits, atol) for n_bits, atol in N_BITS_ATOL_TUPLE_LIST],
+)
+@pytest.mark.parametrize("values", [pytest.param(numpy.random.randn(2000))])
+def test_quant_dequant_update(values, n_bits, atol):
+    """Test the quant and dequant function."""
+
+    quant_array = QuantizedArray(n_bits, values)
+    qvalues = quant_array.quant()
+
+    # Quantized values must be contained between 0 and 2**n_bits
+    assert numpy.max(qvalues) <= 2 ** n_bits - 1
+    assert numpy.min(qvalues) >= 0
+
+    # Dequantized values must be close to original values
+    dequant_values = quant_array.dequant()
+
+    # Check that all values are close
+    assert numpy.isclose(dequant_values, values, atol=atol).all()
+
+    # Test update functions
+    new_values = numpy.array([0.3, 0.5, -1.2, -3.4])
+    new_qvalues_ = quant_array.update_values(new_values)
+
+    # Make sure the shape changed for the qvalues
+    assert new_qvalues_.shape != qvalues.shape
+
+    new_qvalues = numpy.array([1, 4, 7, 29])
+    new_values_updated = quant_array.update_qvalues(new_qvalues)
+
+    # Make sure that we can see at least one change.
+    assert not numpy.array_equal(new_qvalues, new_qvalues_)
+    assert not numpy.array_equal(new_values, new_values_updated)
+
+    # Check that the __call__ returns also the qvalues.
+    assert numpy.array_equal(quant_array(), new_qvalues)