added covariance matrix calculation

1 files changed, 5 insertions, 7 deletions

diff --git a/lin_reg2.awk b/lin_reg2.awk
index dea52b5..7c00fe8 100644
--- a/lin_reg2.awk
+++ b/lin_reg2.awk
@@ -4,7 +4,7 @@
 # simple linear regression between columns
 
 BEGIN {
-    OFS = "%.18g"
+    OFMT = "%.18g"
     sign = "[+-]?"
     decimal = "[0-9]+[.]?[0-9]*"
     fraction = "[.][0-9]*"
@@ -13,13 +13,11 @@ BEGIN {
 }
 
 NR == 1 {
-    header_nf = NF
-    for (n=1; n<=NF; n++) {
-        ($n !~ number) ? header[n] = $n : header[n] = "col" n
-    }
+    for (n=1; n<=NF; n++)
+        ($n ~ number) ? header[n] = "col" n : header[n] = $n
 }
 
-NF != 0 {
+NF > 0 {
     if (NF > nf_max)
         nf_max = NF
 
@@ -39,7 +37,7 @@ NF != 0 {
             sum_delta2[y] += delta[y]*delta[y]
 
             ### sample variance
-            (count[y] - 1) ? var[y] = sum_delta2[y]/(count[y] - 1) : var[y] = 0
+            (count[y] > 1) ? var[y] = sum_delta2[y]/(count[y] - 1) : var[y] = ""
 
             # x = row, y = col
             for (x=1; x<=nf_max; x++) {