math filters!

docsite/rst/playbooks_variables.rst

@@ -310,6 +310,45 @@ To get a random list from an existing  list::
     {{ ['a','b','c']|shuffle }} => ['b','c','a']
 
 note that when used with a non 'listable' item it is a noop, otherwise it always returns a list
+j
+
+.. _math_stuff:
+
+Math
+--------------------
+.. versionadded:: 1.9
+
+To get the absolute value of a number::
+
+    {{ -23 | abs }}
+
+To see if something is actually a number::
+
+    {{ myvar | isnan }}
+
+Rounding::
+
+    {{ myvar | ceil }}
+    {{ myvar | floor }}
+
+Get the logarithm (default is e)::
+
+    {{ myvar | log }}
+
+Get the base 10 logarithm::
+
+    {{ myvar | log(10) }}
+
+Give me the power of 2! (or 5)::
+
+    {{ myvar | pow(2) }}
+    {{ myvar | pow(5) }}
+
+Square root, or the 5th::
+
+    {{ myvar | root }}
+    {{ myvar | root(5) }}
+
 
 .. _other_useful_filters: