added TEXTALIGN command to change the default text alignment

[rrdtool.git] / doc / rrdgraph_rpn.pod

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index dfc9a0b..cf62c08 100644 (file)
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -30,7 +30,7 @@ of your RRD script.
 Example: C<CDEF:mydatabits=mydata,8,*>
 
 This means:  push variable I<mydata>, push the number 8, execute
-the operator I<+>. The operator needs two elements and uses those
+the operator I<*>. The operator needs two elements and uses those
 to return one value.  This value is then stored in I<mydatabits>.
 As you may have guessed, this instruction means nothing more than
 I<mydatabits = mydata * 8>.  The real power of B<RPN> lies in the
@@ -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>
@@ -296,6 +313,6 @@ Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.
 
 =head1 AUTHOR
 
-Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
+Program by Tobias Oetiker E<lt>tobi@oetiker.chE<gt>
 
 This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>