X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=doc%2Frrdgraph_rpn.pod;h=3718349cdbba42e80e991fb461511675cf18b48c;hb=5b7af8fabd296f8e24b91c5c33682681adb15d43;hp=5000d7a1738915277d065318971440624dc65d4d;hpb=342b22c3e74a10d7049285c2cea7383676bcfc95;p=rrdtool.git

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index 5000d7a..3718349 100644
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -127,6 +127,10 @@ B<DEG2RAD, RAD2DEG>
 
 Convert angle in degrees to radians, or radians to degrees.
 
+B<ABS>
+
+Take the absolute value.
+
 =item Set Operations
 
 B<SORT, REV>
@@ -139,7 +143,14 @@ Example: C<CDEF:x=v1,v2,v3,v4,v5,v6,6,SORT,POP,5,REV,POP,+,+,+,4,/> will
 compute the average of the values v1 to v6 after removing the smallest and
 largest.
 
-B<TREND>
+B<AVG>
+
+Pop one element (I<count>) from the stack. Now pop I<count> elements and build the
+average, ignoring all UNKNOWN values in the process.
+
+Example: C<CDEF:x=a,b,c,d,4,AVG>
+
+B<TREND, TRENDNAN>
 
 Create a "sliding window" average of another data series.
 
@@ -163,6 +174,12 @@ average is essentially computed as shown here:
      Value at sample (t1) will be the average between (t1-delay) and (t1)
      Value at sample (t2) will be the average between (t2-delay) and (t2)
 
+TRENDNAN is - in contrast to TREND - NAN-safe. If you use TREND and one 
+source value is NAN the complete sliding window is affected. The TRENDNAN 
+operation ignores all NAN-values in a sliding window and computes the 
+average of the remaining values.
+
+
 =item Special values
 
 B<UNKN>
@@ -240,6 +257,12 @@ the first occurrence of that value in the time component.
 
 Example: C<VDEF:avg=mydata,AVERAGE>
 
+=item STDEV
+
+Returns the standard deviation of the values.
+
+Example: C<VDEF:stdev=mydata,STDEV>
+
 =item LAST, FIRST
 
 Return the last/first value including its time.  The time for