From fae9dcf298dac97f18aa6dcebe211e33b10fd6be Mon Sep 17 00:00:00 2001
From: btracey <bdtinternet@gmail.com>
Date: Thu, 16 May 2013 14:58:23 -0700
Subject: [PATCH] Switched receiver and slice order in cumsum and added check
 for nil receiver

---
 sliceops.go | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sliceops.go b/sliceops.go
index 52d51ff4..d1720f94 100644
--- a/sliceops.go
+++ b/sliceops.go
@@ -61,7 +61,10 @@ func Prod(s []float64) (prod float64) {
 // Finds the cumulative sum of the first i elements in 
 // s and puts them in place into the ith element of the
 // receiver. If the receiver is nil a new slice is created
-func CumSum(s, receiver []float64) []float64 {
+func CumSum(receiver, s []float64) []float64 {
+	if receiver == nil {
+		receiver = make([]float64, len(s))
+	}
 	if len(s) == 0 {
 		return receiver[:0]
 	}