From a6fc0df110e74a4b04bfba4b730a8e596cda344d Mon Sep 17 00:00:00 2001
From: Keith Peters <kp@bit-101.com>
Date: Sat, 1 Jan 2022 19:07:20 -0500
Subject: [PATCH] decrease stdev of gaussrange func

---
 random/random.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/random/random.go b/random/random.go
index 85c344f..7f8c690 100644
--- a/random/random.go
+++ b/random/random.go
@@ -76,7 +76,11 @@ func GaussRange(min, max float64) float64 {
 	rng := (max - min) / 2.0
 	mean := min + rng
 	// a standard deviation of 1.0 will have 99.7% of its values between -3 and +3.
-	std := rng / 3.0
+	// but for 100,000 samples, that's still around 300 points beyond that range.
+	// 99.994% will be between -4 and 4.
+	// for 100,000 samples, that's around 6 outside the range. better.
+	// so we get the standard deviation by dividing the range by 4.0
+	std := rng / 4.0
 	return rand.NormFloat64()*std + mean
 }