Calculated Item Operands

[cronuscronus]

Hello. We love the calculated item option in 1.8.x! We monitor transmitters via SNMP and would like to calculate our voltage standing wave ratio (VSWR) which requires us to take the difference of squares of 2 other items.

To do this we need to have a power operand (5^(1/2)) or the square root (sqrt(5)). Unfortunately it looks like the calculated expressions only support simpler operands such as +, -, / etc...

Does anybody know how to derive the square root or use a power function in a calculated item expression?

[cronuscronus]

Thanks

Thanks for moving this to help.

[ruswold]

Thanks for moving this to help.

I don't know exist this function in calculated item, but i think you may use external check, make script that should return result of you function.

[cronuscronus]

External check

I wound up writing a perl script to run the external check. It is a bummer because the SNMP pollers written for Zabbix are much more efficent as they're written in C. I'm lazy so I use perl.

It would be awesome if we could use all functions available in Math.h in a future release.

[nelsonab]

Open a ticket against the zabbix next project. https://support.zabbix.com

[jhgrc]

Ticket done

Well I did not find any issues ticketted to Zabbix feature requests so I created one.

https://support.zabbix.com/browse/ZBXNEXT-552

Does it cover all needed functions/ideas? I am happy with square root to calculate stddev.

[cronuscronus]

It looks good. Thanks!

[bashman]

Looks good, voted!.