From ebdc5107b8b2bd69a65a34a6276fc64b84d210ec Mon Sep 17 00:00:00 2001
From: Adrien Hopkins <adrien.p.hopkins@gmail.com>
Date: Tue, 5 Sep 2023 11:15:28 -0500
Subject: Remove totative ratio from factors API
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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.
---
 factor_info.go | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

(limited to 'factor_info.go')

diff --git a/factor_info.go b/factor_info.go
index f908b9b..c243048 100644
--- a/factor_info.go
+++ b/factor_info.go
@@ -22,7 +22,7 @@ type FactorInfo struct {
 	Score float64
 	// The number of digits that are totatives (numbers that share no
 	// factors with the radix - they are the worst kind of digits)
-	TotativeCount uint
+	Totient uint
 	// The fraction of digits that are totatives (numbers that share no
 	// factors with the radix - they are the worst kind of digits)
 	TotativeRatio float64
@@ -77,10 +77,13 @@ func GetFactorInfo(radix uint, fullMap bool) *FactorInfo {
 		digitMap = []factors.DigitType{}
 	}
 
+	totativeCount := factors.Totient(radix)
+	totativeRatio := float64(totativeCount) / float64(radix)
+
 	return &FactorInfo{radix, factors.PrimeFactorize(radix),
-		r_factors, factors.Score(radix), factors.TotativeCount(radix),
-		factors.TotativeRatio(radix), factors.BasicRank(radix),
-		r_type_ptr, mtc_ptr, math.Log(float64(radix)), digitMap}
+		r_factors, factors.Score(radix), totativeCount, totativeRatio,
+		factors.BasicRank(radix), r_type_ptr, mtc_ptr,
+		math.Log(float64(radix)), digitMap}
 }
 
 func (fi *FactorInfo) WriteTo(w io.Writer) {
@@ -88,7 +91,7 @@ func (fi *FactorInfo) WriteTo(w io.Writer) {
 	fmt.Fprintf(w, "Factors: %v (Score: %.4f)\n", fi.Factors, fi.Score)
 	fmt.Fprintln(w, "2345 Rank:", fi.BasicRank)
 	fmt.Fprintf(w, "Totative Digit Count: %d (%.3f%%)\n",
-		fi.TotativeCount, fi.TotativeRatio * 100.0)
+		fi.Totient, fi.TotativeRatio * 100.0)
 	if fi.Type != nil {
 		writeTypeMessage(w, *fi.Type)
 	}
@@ -105,7 +108,7 @@ func (fi *FactorInfo) WriteTo(w io.Writer) {
 }
 
 func (fi *FactorInfo) WriteToCompact(w io.Writer) {
-	fmt.Fprintf(w, "%d = %s | σ(n)/n: %.2f | τ(n)/n: %.3f\n",
+	fmt.Fprintf(w, "%d = %s | σ(n)/n: %.2f | φ(n)/n: %.3f\n",
 		fi.Radix, fi.PrimeFactorization, fi.Score, fi.TotativeRatio)
 	if fi.Type != nil {
 		fmt.Fprintf(w, "%s | ", typeAbbrev(*fi.Type))
-- 
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