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path: root/src/pkg/math/rand/zipf.go
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Diffstat (limited to 'src/pkg/math/rand/zipf.go')
-rw-r--r--src/pkg/math/rand/zipf.go6
1 files changed, 4 insertions, 2 deletions
diff --git a/src/pkg/math/rand/zipf.go b/src/pkg/math/rand/zipf.go
index 38e8ec516..8db2c6f5b 100644
--- a/src/pkg/math/rand/zipf.go
+++ b/src/pkg/math/rand/zipf.go
@@ -34,7 +34,6 @@ func (z *Zipf) hinv(x float64) float64 {
// NewZipf returns a Zipf generating variates p(k) on [0, imax]
// proportional to (v+k)**(-s) where s>1 and k>=0, and v>=1.
-//
func NewZipf(r *Rand, s float64, v float64, imax uint64) *Zipf {
z := new(Zipf)
if s <= 1.0 || v < 1 {
@@ -52,9 +51,12 @@ func NewZipf(r *Rand, s float64, v float64, imax uint64) *Zipf {
return z
}
-// Uint64 returns a value drawn from the Zipf distributed described
+// Uint64 returns a value drawn from the Zipf distribution described
// by the Zipf object.
func (z *Zipf) Uint64() uint64 {
+ if z == nil {
+ panic("rand: nil Zipf")
+ }
k := 0.0
for {