1 files changed, 49 insertions, 0 deletions

diff --git a/pyecsca/sca/combine.py b/pyecsca/sca/combine.py
new file mode 100644
index 0000000..c484748
--- /dev/null
+++ b/pyecsca/sca/combine.py
@@ -0,0 +1,49 @@
+import numpy as np
+from public import public
+from typing import Callable, Optional
+
+from .trace import Trace, CombinedTrace
+
+
+@public
+def average(*traces: Trace) -> Optional[CombinedTrace]:
+    """
+    Average `traces`, sample-wise.
+
+    :param traces:
+    :return:
+    """
+    if not traces:
+        return None
+    if len(traces) == 1:
+        return CombinedTrace(None, None, traces[0].samples.copy(), parents=traces)
+    dtype = traces[0].samples.dtype
+    result_samples = np.mean(np.array([trace.samples for trace in traces]), axis=0).astype(dtype)
+    return CombinedTrace(None, None, result_samples, parents=traces)
+
+
+@public
+def conditional_average(*traces: Trace, condition: Callable[[Trace], bool]) -> Optional[CombinedTrace]:
+    """
+    Average `traces` for which the `condition` is True, sample-wise.
+
+    :param traces:
+    :param condition:
+    :return:
+    """
+    return average(*filter(condition, traces))
+
+
+@public
+def standard_deviation(*traces: Trace) -> Optional[CombinedTrace]:
+    """
+    Compute the standard-deviation of the `traces`, sample-wise.
+
+    :param traces:
+    :return:
+    """
+    if not traces:
+        return None
+    dtype = traces[0].samples.dtype
+    result_samples = np.std(np.array([trace.samples for trace in traces]), axis=0).astype(dtype)
+    return CombinedTrace(None, None, result_samples, parents=traces)