STATStream: 
  Frequently Asked Questions
  - What 
    is StatStream? 
  
- Who 
    should use StatStream?  
  
- What 
    functions does StatStream provide?  
  
- What 
    do I need in order to run StatStream?  
  
- Why 
    is StatStream better than the intuitive methods?  
  
- What 
    is the performance gain compared with intuitive methods? 
  
- What can
    I do as a developer? 
  
- My question 
    isn't answered here. Whom should I ask? 
  - What 
    is StatStream?
 
 StatStream is a high performance statistical tool that reports 
correlation information in a real-time way over streaming time series.
 
 
- Who 
    should use StatStream? 
 
 People who require real-time correlaion information over many time series.
 
 
- What 
    functions does StatStream provide? 
 
 StatStream takes streaming data from multiple sources
and outputs stream pairs whose correlation exceeds a threshold
set by the user. Correlation information is reported periodically based again
on a user parameter. The correlation is calculated over a window size which is
yet another parameter.
 
 
- What 
    do I need in order to run StatStream? 
 
 StatStream is built in K, so it can run on Windows/Unix/Linux .
 To run StatStream, K and KDB are necessary. Users can download it from here.
 
 
- Why 
    is StatStream better than the intuitive methods?  
    We use advanced data 
      reduction techniques (e.g. DFT, SVD, Random Projection) to reduce the dimensionality 
      of data vectors and sophisticated data structures to purge the irrelavant 
      data.  
- What 
    is the performance gain compared with intuitive methods?
 Due to its efficient 
      filtering power, StatStream can save substantial computational efforts compred 
      to the intuitive pairwise correlation.
 The following empirical result show the StatStream system performance over 
      a variety of datasets. Minimum recall for approximation method is 99%
 
  
 
 
 
- 
    What can I do as a developer?
 
 In the software package, two files base.k and sketch.k are included. Such tools as DFT, Wavelet and Sketch are
    covered in these two files. A developer can easily integrate these data reduction codes into his/her
    system. Statstream algorithms are implemented in statstream2.k. People can find both DFT based statstream 
    and the sketch based one by tracing the codes in statstream2.k. All the codes are fully documented and thus easy
    to follow. Any questions or feedbacks are welcome.
 
 
- My 
    question isn't answered here. Whom should I ask?
 
 You can send email to shasha@cs.nyu.edu or xiaojian@cs.nyu.edu to contact the authors 
    of the software.
 
Maintained by shasha@cs.nyu.edu 
  
Last Updated Nov. 29, 2005