[libcamera-devel] [PATCH 2/2] utils: tracepoints: ipa call analyzer: Fix std dev calculation for single value

[Paul Elder]

Some IPA calls might only be called once, such as configure(), start(),
stop(), etc. This causes the analyzer to break as stddev() on a single
value is invalid. Set the stddev to zero if there is only one datapoint.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
---
 utils/tracepoints/analyze-ipa-trace.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/utils/tracepoints/analyze-ipa-trace.py b/utils/tracepoints/analyze-ipa-trace.py
index 50fbbf42..cd7e9ffc 100755
--- a/utils/tracepoints/analyze-ipa-trace.py
+++ b/utils/tracepoints/analyze-ipa-trace.py
@@ -58,7 +58,7 @@ def main(argv):
     rows.append(['pipeline:function', 'min', 'max', 'mean', 'stddev'])
     for k, v in samples.items():
         mean = int(stats.mean(v))
-        stddev = int(stats.stdev(v))
+        stddev = int(stats.stdev(v)) if len(v) > 1 else 0
         minv = min(v)
         maxv = max(v)
         rows.append([k, str(minv), str(maxv), str(mean), str(stddev)])
-- 
2.27.0