More Lua binding stuff.

[pkg-rrdtool.git] / doc / rrdgraph_data.txt

diff --git a/doc/rrdgraph_data.txt b/doc/rrdgraph_data.txt
index 8dab92a357335642b6dd4cd4054c38d7d9e4c6b6..338b264d71437403d3ea7e7583e109d8ebc596d6 100644 (file)
--- a/doc/rrdgraph_data.txt
+++ b/doc/rrdgraph_data.txt
@@ -25,7 +25,7 @@ D\bDE\bES\bSC\bCR\bRI\bIP\bPT\bTI\bIO\bON\bN
        ters "A-Z, a-z, 0-9, -,_" and a maximum length of 255 characters.
 
        When picking variable names, make sure you do not choose a name that is
-       already taken by an RPN operator. A save bet it to use lowercase or
+       already taken by an RPN operator. A safe bet it to use lowercase or
        mixedcase names for variables since operators will always be in upper-
        case.
 
@@ -75,7 +75,7 @@ V\bVD\bDE\bEF\bF
 
        Example: "VDEF:avg=mydata,AVERAGE"
 
-       Note that currently only agregation functions work in VDEF rpn expres-
+       Note that currently only aggregation functions work in VDEF rpn expres-
        sions.  Patches to change this are welcome.
 
 C\bCD\bDE\bEF\bF
@@ -89,6 +89,32 @@ C\bCD\bDE\bEF\bF
 
        Example: "CDEF:mydatabits=mydata,8,*"
 
+A\bAb\bbo\bou\but\bt C\bCD\bDE\bEF\bF v\bve\ber\brs\bsu\bus\bs V\bVD\bDE\bEF\bF
+       At some point in processing, R\bRR\bRD\bDt\bto\boo\bol\bl has gathered an array of rates
+       ready to display.
+
+       C\bCD\bDE\bEF\bF works on such an array.  For example, _\bC_\bD_\bE_\bF_\b:_\bn_\be_\bw_\b=_\bd_\bs_\b0_\b,_\b8_\b,_\b* would mul-
+       tiply each of the array members by eight (probably transforming bytes
+       into bits). The result is an array containing the new values.
+
+       V\bVD\bDE\bEF\bF also works on such an array but in a different way.  For example,
+       _\bV_\bD_\bE_\bF_\b:_\bm_\ba_\bx_\b=_\bd_\bs_\b0_\b,_\bM_\bA_\bX_\bI_\bM_\bU_\bM would scan each of the array members and store the
+       maximum value.
+
+       W\bWh\bhe\ben\bn d\bdo\bo y\byo\bou\bu u\bus\bse\be V\bVD\bDE\bEF\bF v\bve\ber\brs\bsu\bus\bs C\bCD\bDE\bEF\bF?\b?
+
+       Use C\bCD\bDE\bEF\bF to transform your data prior to graphing.  In the above exam-
+       ple, we'd use a C\bCD\bDE\bEF\bF to transform bytes to bits before graphing the
+       bits.
+
+       You use a V\bVD\bDE\bEF\bF if you want _\bm_\ba_\bx_\b(_\b1_\b,_\b5_\b,_\b3_\b,_\b2_\b,_\b4_\b) to return five which would be
+       displayed in the graph's legend (to answer, what was the maximum value
+       during the graph period).
+
+       If you want to apply 'complex' operations to the result of a VDEF you
+       have to use a CDEF again since VDEFs only look like RPN expressions,
+       they aren't realy.
+
 S\bSE\bEE\bE A\bAL\bLS\bSO\bO
        rrdgraph gives an overview of how r\brr\brd\bdt\bto\boo\bol\bl g\bgr\bra\bap\bph\bh works.  rrdgraph_data
        describes D\bDE\bEF\bF,C\bCD\bDE\bEF\bF and V\bVD\bDE\bEF\bF in detail.  rrdgraph_rpn describes the R\bRP\bPN\bN
@@ -100,8 +126,9 @@ S\bSE\bEE\bE A\bAL\bLS\bSO\bO
 A\bAU\bUT\bTH\bHO\bOR\bR
        Program by Tobias Oetiker <tobi@oetiker.ch>
 
-       This manual page by Alex van den Bogaerdt <alex@ergens.op.het.net>
+       This manual page by Alex van den Bogaerdt <alex@vandenbogaerdt.nl> with
+       corrections and/or additions by several people
 
 
 
-1.3.1                             2008-03-15                  RRDGRAPH_DATA(1)
+1.3.99909060808                   2009-04-29                  RRDGRAPH_DATA(1)