X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=doc%2Frrdgraph_rpn.pod;h=74ac4ad40751ad898c783bd0185034c7673a0507;hb=a6f5f1b6b90008e73fa57882276bc643c039bb09;hp=4585850bc871abb92cb252823e49e0a0a9e872d0;hpb=cb092381724e4ba8a1f18712fefc541a3d370f99;p=rrdtool.git

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index 4585850..74ac4ad 100644
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -107,11 +107,24 @@ B<ATAN>
 
 Arctangent (output in radians).
 
+B<ATAN2>
+
+Arctangent of y,x components (output in radians).
+This pops one element from the stack, the x (cosine) component, and then
+a second, which is the y (sine) component.
+It then pushes the arctangent of their ratio, resolving the ambiguity between
+quadrants.
+
+Example: C<CDEF:angle=Y,X,ATAN2,RAD2DEG> will convert C<X,Y>
+components into an angle in degrees.
+
 B<FLOOR, CEIL>
 
 Round down or up to the nearest integer.
 
-Z<>
+B<DEG2RAD, RAD2DEG>
+
+Convert angle in degrees to radians, or radians to degrees.
 
 =item Set Operations