Tool Name  :   spectrum_fft

Section 1 :
------------------------------------------------------------------------------
Usage=./spectrum_fft -f data-file 

Uses only fft to get the frequency domain representation.

 --   The time instant specified is in seconds.

      The format of time series is as shown below.

      Example :

             Timestamp | No. of packets
                       |
              0.001    |  5
              0.002    |  10

   0.001,0.002... the first column denotes the time in seconds
   5,10.....  the second column denotes the Number of packets occuring in that  time instant.

 -- It finally produces the following 3 plots.(*)

       1. Time Series
       2. Power Specrum - Depicting the power at different frequencies.,
       3. Cumulative Power Spectrum.
       
  --- A file named Details containing statistical values such as mean,
      standard deviation and 60% quantile frequency is created.

       Examples :

       ./spectrum -f attack_1
       The time series is present in the file attack_1
  
       The plot produced is stored in a file "plot.ps"

       * You may use Ghost-view to view the plots.


Section 1
------------------------------------------------------------------------------
INSTALLATION :
--------------
        tar xvfz spectrum-0.2.tar.gz
        cd spectrum-0.2
        ./configure
        make

Section 2
-------------------------------------------------------------------------------

INSTALLATION OF FFTW LIBRARY
----------------------------

This tool requires the fftw library to be installed as it uses fftw to 
find the fast fourier transform of a set of samples.

To install the library.

1.Link : www.fftw.org/fftw-3.0.1.tar.gz

Use : ./configure --prefix to install in a local directory called fft.

The include file fftw3.h should be present in the path
   spectrum-0.2/fftw-3.0.1/fft/include/fftw3.h

The path of the library should be :
   spectrum-0.2/fftw-3.0.1/fft/lib/libfftw3.a


