ReadObs2

 Reads the data corresponding to an observation from a file.

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 Parameters
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 fileName - the name of the text file containing the data describing the
            observation
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 Returned values
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 obs - the structure describing the observation 
       It uses the observation structure type v. 2.0 presented below:
       obs--name
          |-mf(i)--name
                 |-type
                 |-params
                 |-paramsy
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 Zsolt Csaba Johanyák, johanyak.csaba@gamf.kefo.hu, v. 2.0,  20. April 2006.