Data commit

Task/Cumulative-standard-deviation/AWK/cumulative-standard-deviation.awk

@@ -0,0 +1,19 @@
+# syntax: GAWK -f STANDARD_DEVIATION.AWK
+BEGIN {
+    n = split("2,4,4,4,5,5,7,9",arr,",")
+    for (i=1; i<=n; i++) {
+      temp[i] = arr[i]
+      printf("%g %g\n",arr[i],stdev(temp))
+    }
+    exit(0)
+}
+function stdev(arr,  i,n,s1,s2,variance,x) {
+    for (i in arr) {
+      n++
+      x = arr[i]
+      s1 += x ^ 2
+      s2 += x
+    }
+    variance = ((n * s1) - (s2 ^ 2)) / (n ^ 2)
+    return(sqrt(variance))
+}