X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=doc%2Frrdgraph_rpn.html;h=bed66325f395102095325ac47665002bb4ccf7c1;hb=refs%2Ftags%2Fupstream%2F1.3.8;hp=2aeac6710341501b860a1db2f6210ee576e6093c;hpb=1559397b94b4af3de73cfa23c04be31d8bee53e7;p=pkg-rrdtool.git diff --git a/doc/rrdgraph_rpn.html b/doc/rrdgraph_rpn.html index 2aeac67..bed6632 100644 --- a/doc/rrdgraph_rpn.html +++ b/doc/rrdgraph_rpn.html @@ -9,8 +9,10 @@ -

+ +

+ + +

@@ -53,7 +59,7 @@ data point on the graph. VDEF instructions work on an entire da one run. Note, that currently VDEF instructions only support a limited list of functions.

Example: VDEF:maximum=mydata,MAXIMUM

This will set variable ``maximum'' which you now can use in the rest +

This will set variable "maximum" which you now can use in the rest of your RRD script.

Example: CDEF:mydatabits=mydata,8,*

This means: push variable mydata, push the number 8, execute @@ -71,7 +77,7 @@ would do a = b, 3, +, 5, * without the need for parentheses.

OPERATORS

Boolean operators

LT, LE, GT, GE, EQ, NE

@@ -89,7 +95,7 @@ mean that any value other than 0 is considered to be true.

Example: A,B,C,IF should be read as if (A) then (B) else (C)

Comparing values

MIN, MAX

@@ -109,7 +115,7 @@ will always return an unknown

alpha is lower than 0 or if it is higher than 100.

Arithmetics

+, -, *, /, %

@@ -137,7 +143,7 @@ components into an angle in degrees.

ABS

Take the absolute value.

Set Operations

SORT, REV

@@ -152,7 +158,7 @@ largest.

average, ignoring all UNKNOWN values in the process.

Example: CDEF:x=a,b,c,d,4,AVG

TREND, TRENDNAN

Create a ``sliding window'' average of another data series.

Create a "sliding window" average of another data series.

Usage: CDEF:smoothed=x,1800,TREND

This will create a half-hour (1800 second) sliding window average of x. The @@ -175,7 +181,7 @@ 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.

Special values

UNKN

@@ -200,7 +206,7 @@ number 2 if it is the second, and so on. This special value allows you to make calculations based on the position of the value within the data set. This function cannot be used in VDEF instructions.

Time

Time inside RRDtool is measured in seconds since the epoch. The @@ -215,7 +221,7 @@ valid at that time including daylight saving time if your OS supports it, and pushes the result on the stack. There is an elaborate example in the examples section below on how to use this.

Processing the stack directly

DUP, POP, EXC

@@ -230,20 +236,20 @@ top elements.

VARIABLES

These operators work only on VDEF statements. Note that currently ONLY these work for VDEF.

MAXIMUM, MINIMUM, AVERAGE

Return the corresponding value, MAXIMUM and MINIMUM also return the first occurrence of that value in the time component.

Example: VDEF:avg=mydata,AVERAGE

STDEV

Returns the standard deviation of the values.

Example: VDEF:stdev=mydata,STDEV

LAST, FIRST

Return the last/first value including its time. The time for @@ -251,7 +257,7 @@ FIRST is actually the start of the corresponding interval, whereas LAST returns the end of the corresponding interval.

Example: VDEF:first=mydata,FIRST

TOTAL

Returns the rate from each defined time slot multiplied with the @@ -260,7 +266,7 @@ when you have logged bytes per second. The time component returns the number of seconds.

Example: VDEF:total=mydata,TOTAL

PERCENT

This should follow a DEF or CDEF vname. The vname is popped, @@ -274,7 +280,7 @@ finite numbers and are always more than the Unknown numbers. (NaN < -INF < finite values < INF)

Example: VDEF:perc95=mydata,95,PERCENT

LSLSLOPE, LSLINT, LSLCORREL

Return the parameters for a Least Squares Line (y = mx +b)