Data commit

Task/Cumulative-standard-deviation/Raku/cumulative-standard-deviation-1.raku

@@ -0,0 +1,12 @@
+sub sd (@a) {
+    my $mean = @a R/ [+] @a;
+    sqrt @a R/ [+] map (* - $mean)², @a;
+}
+
+sub sdaccum {
+    my @a;
+    return { push @a, $^x; sd @a; };
+}
+
+my &f = sdaccum;
+say f $_ for 2, 4, 4, 4, 5, 5, 7, 9;

Task/Cumulative-standard-deviation/Raku/cumulative-standard-deviation-2.raku

@@ -0,0 +1,8 @@
+sub stddev($x) {
+    sqrt
+        ( .[2] += $x²) / ++.[0]
+      - ((.[1] += $x ) /   .[0])²
+    given state @;
+}
+
+say .&stddev for <2 4 4 4 5 5 7 9>;