Remove totative ratio from factors API

This value can easily be calculated as φ(r)/r.  There is no need to have
this now that I have a function φ(r) (renamed to its mathematical name,
Totient).

I removed totative ratio instead of totient because, while it is more
important, totient is an integer while totative ratio is a float.  This
means that the totative ratio can be calculated exactly from the
totient, but not the other way round.

1 files changed, 12 insertions, 4 deletions

diff --git a/factors/factors_test.go b/factors/factors_test.go
index af91e70..745fd2c 100644
--- a/factors/factors_test.go
+++ b/factors/factors_test.go
@@ -67,17 +67,25 @@ var totativeRatioCases = map[uint]float64{
 	30: 4.0 / 15.0, 60: 4.0 / 15.0, 120: 4.0 / 15.0,
 }
 
+func totativeRatio(n uint) float64 {
+	if n == 0 {
+		panic("0 has no totative ratio!")
+	}
+
+	return float64(Totient(n)) / float64(n)
+}
+
 func TestTotativeRatio(t *testing.T) {
-	tableTest(t, TotativeRatio, totativeRatioCases, stdEquals, "TotativeRatio")
+	tableTest(t, totativeRatio, totativeRatioCases, stdEquals, "TotativeRatio")
 }
 
-var totativeCountCases = map[uint]uint{
-	1: 1, 2: 1, 3: 2, 4: 2, 6: 2, 7: 6, 8: 4, 12: 4,
+var totientCases = map[uint]uint{
+	0: 0, 1: 1, 2: 1, 3: 2, 4: 2, 6: 2, 7: 6, 8: 4, 12: 4,
 	14: 6, 15: 8, 30: 8, 60: 16, 120: 32,
 }
 
 func TestTotativeCount(t *testing.T) {
-	tableTest(t, TotativeCount, totativeCountCases, stdEquals, "TotativeCount")
+	tableTest(t, Totient, totientCases, stdEquals, "Totient")
 }
 
 var factorScoreCases = map[uint]float64{