Data update

Task/Cumulative-standard-deviation/DuckDB/cumulative-standard-deviation.duckdb

@@ -0,0 +1,7 @@
+# Create a table with the data together with a sequence number
+CREATE OR REPLACE TABLE t AS
+  SELECT generate_subscripts(l, 1) as id, unnest(l)::DOUBLE as x,
+  from (values ([2,4,4,4,5,5,7,9])) tbl(l) ;
+
+# Compute the rolling standard deviations without the Bessel adjustment:
+SELECT *, stddev_pop(x) OVER (ORDER BY id)  as 'cumulative stddev' FROM t;