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  • Description
  • Computes the difference between two evoked potential files (.p). The output is a new evoked potential file (.p).

  • Usage
  • epdiff

    This program uses an interactive input.The questions are as follows (questions (program) are italic, answers (user) are bold):
    Name of the first .p file (no .p extension) or return to quit :
    myfile1
    Name of the .p file to be subtracted (no .p extension) :
    myfile2
    Name of the resulting .p file (no .p extension) :
    myoutfile
    Name of the first .p file (no .p extension) or return to quit :



  • Fields of parameter file and example

  • Examples
  • This program will compute the difference between myfile1, myfile2 and will store the results in myoutputfile. The number of channel, the number of samples, the analysis duration, the number of pre-stimulus samples and the sampling period must be the same in all input files.

  • Comments
    1. It should be noted that the ep file name are entered without the .p extension.
    2. Possible error messages:
    3. Incompatible epfile : p_xe[n]
      the file you just enter is not compatible with the previous ones. The 'n' indicates which field of the *.p header is wrong:
      - 1 the number of channel,
      - 2 the number of samples,
      - 3 the epoch duration,
      - 4 the number of pre-stimulus samples,
      - 5 the sampling period.


  • Current version
  • 1.05 24-01-2011

  • History
    • 1.00 09-12-2001 (PEA) : 1st documented version.
    • 1.01 01-02-2002 (PEA) : minor modification.
    • 1.02 23-10-2003 (PEA) : minor modification.
    • 1.03 13-08-2007 (PEA) : minor modification.
    • 1.04 29-09-2010 (PEA) : updates to use cmake and free release of Elan.
    • 1.05 24-01-2011 (PEA) : removes static allocation for reading EP file.


  • Files
  • $ELANPATH/bin/epdiff

  • See also
  • epavg