Tool Name  :   spectrum

Section 1 :
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Two column data :

If the input data file contains two columns the time and amplitude values of the signal.

Usage=./spectrum -f data-file 

      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.

One column data :

If the input data file contains one column data i.e only the amplitudes of the signal then
the user has to supply the sampling frequency as a command line argument.

Usage=./spectrum -f data-file -s sampling-frequency 

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

Section 2
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INSTALLATION OF FFTW LIBRARY
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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

Section 3
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The sample files sam_input1.ps and samp_input2.ps show the frequency spectrum of a 200 Hz sine wave.
10,000 samples of a sine wave of frequency 200 Hz are considered and the sampling frequency used is 1000 Hz.




