added min and max to mean and mean_avg, fixed regex bugs in mean

1 files changed, 14 insertions, 15 deletions

diff --git a/mean.awk b/mean.awk
index 816208c..b6a794e 100644
--- a/mean.awk
+++ b/mean.awk
@@ -1,36 +1,35 @@
 #!/usr/bin/awk -f

 

 ### mean.awk

-# calculate mean average

+# calculate mean average of serialized numbers

 

 BEGIN {

     OFS = FS

-    sign = "[+-±]?"

+    sign = "[+-]?"

     decimal = "[0-9]+[.]?[0-9]*"

-    fraction = "[.][0-9]*"

+    fraction = "[.][0-9]+"

     exponent = "([Ee]" sign "[0-9]+)?"

     number = "^" sign "(" decimal "|" fraction ")" exponent "$"

 }

 

 # Welford's 'online' algorithm for variance

 NF > 0 {

-    for (m=1; m<=NF; m++) {

-        if (m ~ number) {

+    for (n=1; n<=NF; n++) {

+        if ($n ~ number) {

             count += 1

-            delta0 = $m - mean

-            mean = mean + delta0/count

-            delta1 = $m - mean

-            M2 = M2 + delta0*delta1

-            if (count > 1)

-                var = M2/(count - 1)

-            else

-                var = "nan"

+            (count == 1 || $n < min) ? min = $n : min = min

+            (count == 1 || $n > max) ? max = $n : max = max

+            delta0 = $n - mean

+            mean += delta0/count

+            delta1 = $n - mean

+            M2 += delta0*delta1

+            (count > 1) ? var = M2/(count - 1) : var = "nan"

         }

     }

 }

 

 END {

-    print "mean", "std_err", "std_dev", "count"

-    print mean, sqrt(var/count), sqrt(var), count

+    print "mean", "std_err", "std_dev", "min", "max", "count"

+    print mean, sqrt(var/count), sqrt(var), min, max, count

 }