Data update

Task/Averages-Simple-moving-average/Jq/averages-simple-moving-average.jq

@@ -0,0 +1,30 @@
+# The input should be a JSON object with a key named "period".
+# The output is a JSON object with a key named "average" giving the SMA.
+def sma($x):
+  def average:
+    .n as $n
+    | if $n == null or $n == 0 then . + {n: 1, average: $x}
+      else .average |= (. * $n + $x) / ($n + 1)
+      | .n += 1
+      end;
+
+  if . == null or (.period and .period < 1)
+  then "The initial call to sma/1 must specify the period properly" | error
+  elif .n and .n < 0 then "Invalid value of .n" | error
+  elif (.period | isinfinite) then average
+  elif .n == null or .n == 0 then . + {n: 1, average: $x, array: [$x]}
+  else .n as $n
+  | if $n < .period
+    then .array += [$x]
+    | .n += 1
+    else .array |= .[1:] + [$x]
+    end
+  | .average = (.array | (add/length))
+  end;
+
+# Call sma($x) for the 11 numbers 0, 1, ... 10.
+def example($period):
+ reduce range(0;11) as $x({period: $period}; sma($x))
+ | .average ;
+
+example(11), example(infinite)