add metric on quantized output

frontends/concrete-python/examples/tfhers-ml/README.md

@@ -89,6 +89,12 @@ python -c "print(','.join(map(lambda x: str(x << 10), [$(cat $TDIR/result_plaint
 ../../tests/tfhers-utils/target/release/tfhers_utils dequantize --value=$(cat $TDIR/rescaled_plaintext) --shape=5,3 --config ./output_quantizer.json
 ```
 
+## Compute error
+
+```sh
+python compute_error.py --plaintext-file "$TDIR/rescaled_plaintext" --quantized-predictions-file "test_values.json"
+```
+
 ## Clean tmpdir
 
 ```sh

frontends/concrete-python/examples/tfhers-ml/compute_error.py

@@ -0,0 +1,47 @@
+import json
+import click
+
+@click.command()
+@click.option('--plaintext-file', '-p', required=True, help='Path to the rescaled plaintext values file.')
+@click.option('--quantized-predictions-file', '-q', required=True, help='Path to the test_values.json file containing quantized predictions.')
+def compute_error(plaintext_file, quantized_predictions_file):
+    """Compute the error between decrypted rescaled values and quantized predictions."""
+    # Read rescaled plaintext values from plaintext_file
+    with open(plaintext_file) as f:
+        rescaled_plaintext_values = [int(x) for x in f.read().strip().split(',')]
+
+    # Read quantized_predictions from quantized_predictions_file
+    with open(quantized_predictions_file) as f:
+        data = json.load(f)
+        quantized_predictions = data['quantized_predictions']
+
+    # Flatten quantized_predictions
+    quantized_predictions_flat = [int(x) for sublist in quantized_predictions for x in sublist]
+
+    # Round down 10 bits using (x // (1 << 10)) * (1 << 10)
+    rounded_quantized_predictions = [
+        (x // (1 << 10)) * (1 << 10) for x in quantized_predictions_flat
+    ]
+
+    # Compare rescaled_plaintext_values with rounded_quantized_predictions
+    num_differences = 0
+    total_values = len(rescaled_plaintext_values)
+    errors = []
+    for i in range(total_values):
+        a = rescaled_plaintext_values[i]
+        b = rounded_quantized_predictions[i]
+        print(f"output: {a}, expected: {b}")
+        if a != b:
+            num_differences += 1
+            error_in_units = round((a - b) / (1 << 10))
+            errors.append((i, error_in_units))
+
+    print("Number of differing values: {}".format(num_differences))
+    print("Total values compared: {}".format(total_values))
+    if num_differences > 0:
+        print("Differences (index, error in units of 2^10):")
+        for idx, error_in_units in errors:
+            print("Index {}: error = {}".format(idx, error_in_units))
+
+if __name__ == '__main__':
+    compute_error()

frontends/concrete-python/examples/tfhers-ml/example.py

@@ -88,6 +88,9 @@ def ccompilee():
     # Add the auto-adjustment before compilation
     fhe.AutoRounder.adjust(compute, inputset)
 
+    # Print the number of bits rounded
+    print(f"lsbs_to_remove: {rounder.lsbs_to_remove}")
+
     circuit = compiler.compile(inputset, show_graph=True, show_mlir=True)
 
     tfhers_bridge = tfhers.new_bridge(circuit=circuit)

frontends/concrete-python/examples/tfhers-ml/test_values.json

@@ -0,0 +1,120 @@
+{
+  "input_fp32_values": [
+    [
+      5.1,
+      3.5,
+      1.4,
+      0.2
+    ],
+    [
+      4.9,
+      3.0,
+      1.4,
+      0.2
+    ],
+    [
+      4.7,
+      3.2,
+      1.3,
+      0.2
+    ],
+    [
+      4.6,
+      3.1,
+      1.5,
+      0.2
+    ],
+    [
+      5.0,
+      3.6,
+      1.4,
+      0.2
+    ]
+  ],
+  "input_quantized_values": [
+    [
+      36,
+      -17,
+      -85,
+      -124
+    ],
+    [
+      29,
+      -33,
+      -85,
+      -124
+    ],
+    [
+      23,
+      -26,
+      -88,
+      -124
+    ],
+    [
+      19,
+      -30,
+      -82,
+      -124
+    ],
+    [
+      32,
+      -13,
+      -85,
+      -124
+    ]
+  ],
+  "quantized_predictions": [
+    [
+      50675,
+      17162,
+      -67716
+    ],
+    [
+      50063,
+      17220,
+      -67169
+    ],
+    [
+      50881,
+      16989,
+      -67759
+    ],
+    [
+      50035,
+      16885,
+      -66819
+    ],
+    [
+      50943,
+      16998,
+      -67824
+    ]
+  ],
+  "dequantized_predictions": [
+    [
+      7.317482754272291,
+      3.3779769146644965,
+      -10.61937344282465
+    ],
+    [
+      6.932649941209247,
+      3.4144479982554388,
+      -10.275413395854903
+    ],
+    [
+      7.44701798219874,
+      3.269192475677721,
+      -10.64641234962483
+    ],
+    [
+      6.915043211199826,
+      3.2037960499284455,
+      -10.055329270737149
+    ],
+    [
+      7.486004312933885,
+      3.2748517817521776,
+      -10.687285115718128
+    ]
+  ]
+}