Fix BBI data provider underflow bug when computing standard deviation

2026-10-16 07:19:13 +08:00 · 2015-07-24 16:45:18 -04:00
parent 24360176bd
commit e36d1c2e0e
1 changed files with 1 additions and 1 deletions
@@ -1180,7 +1180,7 @@ class BBIDataProvider( GenomeDataProvider ):
                    # Compute $\mu \pm 2\sigma$ to provide an estimate for upper and lower
                    # bounds that contain ~95% of the data.
                    mean = summary.sum_data[0] / valid_count
-                    var = summary.sum_squares[0] - mean
+                    var = max( summary.sum_squares[0] - mean, 0 ) # Prevent variance underflow.
                    if valid_count > 1:
                        var /= valid_count - 1
                    sd = math.sqrt( var )