[rrd-users] Re: CDEF question

Alex van den Bogaerdt alex at slot.hollandcasino.nl
Thu Mar 8 22:48:34 MET 2001

Christian Pearce wrote:

> I am going to say yes.  I am trying to figure out a way of replacing nan
> values with zero.  This is what I tried.
> test=test1,UNKN,EQ,test1,0,IF

According to the rrdtool tutorial, the manual page and the rpn tutorial
this will check: if test1 equals unknown, if so return test1, else 0.
So, the outcome will allways be unknown or zero.

> test=test1,test1,0,IF

This will return test1 if test1 does not equal zero, else it will return

> test=test1,UN,test1,0,IF

See first eqpression.

> I thought the last one would work but to no avail.  The problem I am
> having is I have to add to values together but it is possiable for either
> one of these values to be nan.

Then you should check, and alter if necessary, both variables.
However, you shouldn't say that 123 + an unknown number == 123.
In this case it may be better to make the sum equal to 0 if it is
unknown -->  a,b,+,DUP,UN,EXC,0,EXC,IF

 / alex at slot.hollandcasino.nl                  alex at ergens.op.het.net \
| work                                                         private |
| My employer is capable of speaking therefore I speak only for myself |
| Technical questions sent directly to me will be nuked. Use the list. | 
| http://faq.mrtg.org/                                                 |
| http://rrdtool.eu.org  --> tutorial                                  |

Unsubscribe mailto:rrd-users-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:rrd-users-request at list.ee.ethz.ch?subject=help
Archive     http://www.ee.ethz.ch/~slist/rrd-users
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi

More information about the rrd-users mailing list