I know of the feature in settings to completely ignore certain traffic. But what if I need that traffic for testing purposes (to see sonething is working), but do not need it afterwards? A custom filter to apply, for instance, to comb out one or several IP address(es) when you watch your data, a filter you can then remove when you need to see everything.
I was to ask this as a feature. 
OK, I put it over there now. Thanks!
well, you can already remove IP filtering from settings or Delete ignore cookie… ?
matt I guess he means things like, exclude a certain ip or even a country (or anything else) from visible stats no mater if it exists in database. this way you can do many things with the stats.
it is the feature requst: Segmentation in Piwik, phase 2: UI · Issue #2092 · matomo-org/matomo · GitHub
nice. it points to this one I think Segmentation: implement UI for adding/editing segments, and switching segments · Issue #2135 · matomo-org/matomo · GitHub
is there any forum related topic to reply there with ideas on this or just use the above page ?
truth is u speak very technical there
Happy New Year! If you are still using Piwik and interested in the awesome new feature of “Creating a Custom Segment in Piwik and apply to reports in Real time!” we need YOUR help, with a little or big donation at: http://crowdfunding.piwik.org/custom-segments-editor/
This will allow to dynamically add or edit, a new set of rules for example “Show all visitors from USA and using Firefox and using Google”. This will be done via a simple to use interface. See screenshots and more info here: http://crowdfunding.piwik.org/custom-segments-editor/
We are crowd funding the future of Piwik and this feature in particular. With your help we can do it.
Thanks
Matthieu