multinom

2 files changed, 25 insertions, 0 deletions

diff --git a/ruby/multinom.rb b/ruby/multinom.rb
new file mode 100755
index 0000000..afee4b7
--- /dev/null
+++ b/ruby/multinom.rb
@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+
+def fak n
+  r = 1
+  (1).upto(n) { |i| r = r*i }
+  return r
+end
+
+def multinom n, ks, ps
+  b = fak(n)
+  prod = 1
+  ks.each { |k| prod = prod*fak(k) }
+  b = b/prod
+  ps.each_with_index { |p,j|
+    b = b*p**ks[j]
+  }
+  return b
+end
+
+puts multinom(ARGV[0].to_f, ARGV[1].split.map{|i| i.to_f}, ARGV[2].split.map{|i| i.to_f})
+
diff --git a/ruby/multinom.sh b/ruby/multinom.sh
new file mode 100644
index 0000000..f78d4d5
--- /dev/null
+++ b/ruby/multinom.sh
@@ -0,0 +1,4 @@
+#!/bin/zsh -x
+
+./multinom.rb 10 "0 10" "0.1 0.9"
+