Yes, thats what I meant. So we can apply this function to existing windows right?
On Fri, Oct 17, 2014 at 5:37 PM, Manoj Gunawardena <man...@wso2.com> wrote: > Hi Seshika, > > Did u mean, this getFrequencies function, should able to accept another > argument, that mean if this apply to a time window if window lenght is 1 > day, this function will return last 5 hrs frequency of a day. > Is your requirement can fulfill with existing window length or time > parameters? > > ex -: if you need to extract frequency of last 5 hrs , apply this fuction > to 5hrs time window > > > Thanks > > On Fri, Oct 17, 2014 at 5:10 PM, Seshika Fernando <sesh...@wso2.com> > wrote: > >> When considering the usecases for this, getting the frequency during a >> particular time period will be very useful. (eg:- trading frequency of a >> different stocks/products during the last 5 hours) >> Does your custom transformer support this? Or does it always take all >> events for the frequency calculations? >> >> On Fri, Oct 17, 2014 at 4:32 PM, Rajeevan Vimalanathan < >> rajeev...@wso2.com> wrote: >> >>> We are planning to integrate Frequency algorithm as a part of training >>> project[1] with Siddhi CEP. >>> >>> Basically this is the algorithm calculates the number of occurrences >>> (frequency) of a specified attribute for a given input stream in CEP. >>> >>> We have selected a Siddhi Transformer to implement this functionality by >>> using stream-lib[2] as a third party library which is licensed under Apache >>> Software Foundation. >>> >>> Standard Siddhi query for using this algorithm would look like below, >>> >>> * from >>> inputStream#transform.custom:getFrequencies(desiredAttribute)select >>> desiredAttribute, >>> frequency* >>> *insert into frequencyStream;* >>> >>> Where, >>> >>> inputStream : Input Stream to CEP >>> >>> custom : namespace >>> >>> getFrequencies : function name >>> >>> desiredAttribute : Attribute name from input stream for which >>> frequencies need to be calculated >>> frequencyStream : Output Stream from CEP that contains frequency related >>> information >>> >>> The stream-lib library supports only Top-K and cardinality algorithms >>> directly where the Top-K algorithm takes ‘K’ value as an argument from user >>> and gives distinct K number of elements which have highest frequency values >>> with related frequency values. The library provides no functions for >>> getting frequencies of all elements. So what we are planning to do is >>> giving a maximum integer value(Integer.MAX_VALUE) as an argument to the >>> Top-K algorithm. So obviously, we will be able to get frequencies for all >>> distinct event attributes provided that distinct event attribute count does >>> not exceed Integer.MAX_VALUE value. >>> >>> There won’t be any memory issues as giving of Integer.MAX_VALUE for >>> Top-K algorithm because it is increasing it’s bucket size dynamically as >>> new distinct events come. >>> >>> We have already implemented the above design and basic testings seem to >>> be ok. >>> >>> Kindly comment on the implementation. >>> >>> [1] - https://redmine.wso2.com/issues/2884 >>> >>> [2] - https://github.com/addthis/stream-lib >>> >>> -- >>> Best Regards, >>> V.Rajeevan >>> Software Engineer, >>> WSO2 Inc. :http://wso2.com >>> >>> Mobile : +94 773090875 >>> Email : rajeev...@wso2.com >>> >>> _______________________________________________ >>> Architecture mailing list >>> Architecture@wso2.org >>> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture >>> >>> >> >> _______________________________________________ >> Architecture mailing list >> Architecture@wso2.org >> https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture >> >> > > > -- > Manoj Gunawardena > Tech Lead > WSO2, Inc.: http://wso2.com > lean.enterprise.middleware > Mobile : +94 77 2291643 > > _______________________________________________ > Architecture mailing list > Architecture@wso2.org > https://mail.wso2.org/cgi-bin/mailman/listinfo/architecture > >
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