Manipulating data using conditionals, eval, or custom commands?

[nickbyrne]

We have enterprise data which we are querying and running through some 'hypothetical' business situations. So, ideally we'd like to perturb the data from time to time (and within date/time brackets) so as to inspect what that might look like in a report/graph.

Has anyone come across something like this? Can you use conditionals within streaming custom command say, or EVAL? By this I mean we could even get away with using an if statement to check whether the event occurred within a daterange, and if so, apply some logic to it and output to table using EVAL.

Looking for what the best approach here might be?

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Edit: So consider 30 days of data. I might want to artificially raise 'bandwidth' by 20% for days 7 through
15.

[sideview]

You can use the if() function or the case() function in the eval command. When used in conjunction with all the other functions available to the eval command, you can do a wide assortment of manipulations.

For instance if you want to add a custom field to the events that reflects whether they occurred in the last 24 hours or merely in the last week or just in the last month, you could do

| eval period=case(_time>relative_time(now(), "-24h"),"last 24 hours",_time>relative_time(now(),"-7d"), "last 7 days",_time>relative_time(now(),"-30d"),"last 30 days")

http://docs.splunk.com/Documentation/Splunk/6.1.3/SearchReference/CommonEvalFunctions

Effectively this gives you powerful tools to filter, transform and change the key value pairs in your result rows. Trying to conditionally present those results however, takes you into a different realm. There you can use the Sideview modules ResultsValueSetter to pull dynamic field values down to the UI, and other modules to affect presentation or to present them entirely different ways. A pretty different topic though.