Add trace stretch function.

3 files changed, 69 insertions, 7 deletions

diff --git a/profile_orders.py b/profile_orders.py
new file mode 100644
index 0000000..658b054
--- /dev/null
+++ b/profile_orders.py
@@ -0,0 +1,40 @@
+import numpy as np

+from numpy import random as npr

+from pyecsca.sca.stacked_traces import GPUTraceManager

+from pyecsca.sca.stacked_traces.stacked_traces import StackedTraces

+from test.sca.perf_stacked_combine import (

+    generate_dataset,

+    report,

+    timed,

+)

+

+NREPS = 100

+

+

+def main():

+    rm_times_storage = []

+    cm_times_storage = []

+

+    for _ in range(NREPS):

+        rm_samples = generate_dataset(npr.default_rng(), 2 ** 10, 2 ** 15)

+        rm_data = StackedTraces(rm_samples)

+        rm_tm = GPUTraceManager(

+            rm_data,

+        )

+        timed(rm_times_storage, log=True)(rm_tm.average)()

+

+        cm_samples = np.array(rm_samples, order="F")

+        cm_data = StackedTraces(cm_samples)

+        cm_tm = GPUTraceManager(

+            cm_data,

+        )

+        timed(cm_times_storage, log=True)(cm_tm.average)()

+

+    rm_times = np.array([duration for _, duration in rm_times_storage[1:]])

+    cm_times = np.array([duration for _, duration in cm_times_storage[1:]])

+    print(f"Row major:\n\t{np.mean(rm_times) / 1e6:.3f}ms ± {np.std(rm_times) / 1e6:.3f}ms")

+    print(f"Col major:\n\t{np.mean(cm_times) / 1e6:.3f}ms ± {np.std(cm_times) / 1e6:.3f}ms")

+

+

+if __name__ == "__main__":

+    main()

diff --git a/pyecsca/sca/trace/edit.py b/pyecsca/sca/trace/edit.py
index 52338e6..88e186f 100644
--- a/pyecsca/sca/trace/edit.py
+++ b/pyecsca/sca/trace/edit.py
@@ -11,9 +11,9 @@ def trim(trace: Trace, start: Optional[int] = None, end: Optional[int] = None) -
     """
     Trim the `trace` samples, output contains samples between the `start` and `end` indices.
 
-    :param trace:
-    :param start:
-    :param end:
+    :param trace: The trace to trim.
+    :param start: Starting index (inclusive).
+    :param end: Ending index (exclusive).
     :return:
     """
     if start is None:
@@ -30,7 +30,7 @@ def reverse(trace: Trace) -> Trace:
     """
     Reverse the samples of the `trace`.
 
-    :param trace:
+    :param trace: The trace to reverse.
     :return:
     """
     return trace.with_samples(np.flipud(trace.samples))
@@ -45,9 +45,9 @@ def pad(
     """
     Pad the samples of the `trace` by `values` at the beginning and end.
 
-    :param trace:
+    :param trace: The trace to pad.
     :param lengths: How much to pad at the beginning and end, either symmetric (if integer) or asymmetric (if tuple).
-    :param values: What value to pad with,  either symmetric or asymmetric (if tuple).
+    :param values: What value to pad with, either symmetric or asymmetric (if tuple).
     :return:
     """
     if not isinstance(lengths, tuple):
@@ -57,3 +57,17 @@ def pad(
     return trace.with_samples(
         np.pad(trace.samples, lengths, "constant", constant_values=values)
     )
+
+
+@public
+def stretch(trace: Trace, length: int) -> Trace:
+    """
+    Stretch (or squeeze) a trace linearly to fit a given length.
+
+    :param trace: The trace to stretch (or squeeze).
+    :param length: The length it should be.
+    :return:
+    """
+    current_indices = np.arange(len(trace))
+    target_indices = np.linspace(0, len(trace) - 1, length)
+    return trace.with_samples(np.interp(target_indices, current_indices, trace.samples))
\ No newline at end of file
diff --git a/test/sca/test_edit.py b/test/sca/test_edit.py
index db80393..98bba09 100644
--- a/test/sca/test_edit.py
+++ b/test/sca/test_edit.py
@@ -1,7 +1,7 @@
 import numpy as np
 import pytest
 
-from pyecsca.sca import Trace, trim, reverse, pad
+from pyecsca.sca import Trace, trim, reverse, pad, stretch
 
 
 @pytest.fixture()
@@ -48,3 +48,11 @@ def test_pad(trace):
         result.samples,
         np.array([0, 10, 20, 30, 40, 50, 0, 0, 0], dtype=np.dtype("i1")),
     )
+
+
+def test_stretch(trace):
+    result = stretch(trace, 10)
+    assert result is not None
+    assert np.min(result) == min(trace)
+    assert np.max(result) == max(trace)
+    assert len(result) == 10