1 files changed, 1 insertions, 0 deletions
diff --git a/js/util.js b/js/util.js
index f1fd3c2..c3940d3 100644
--- a/js/util.js
+++ b/js/util.js
@@ -46,6 +46,7 @@ function random(){ return Math.random() }
 function rand(n){ return (Math.random()*n) }
 function randint(n){ return rand(n)|0 }
 function randrange(a,b){ return a + rand(b-a) }
+function randsign(){ return random() >= 0.5 ? -1 : 1 }
 function choice(a){ return a[randint(a.length)] }
 function deg(n){ return n*180/PI }
 function rad(n){ return n*PI/180 }