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  • Description
  • Conversion tool for coordinates of sensors (VSM-CTF Omega 275 channels) to Elan .coil format (text file).

  • Usage
  • ctf275_2coil myctfdirectory.ds mycoilfile [-withREF]

    with :

    • myctfdirectory.ds : CTF dataset directory (with extension).
    • mycoilfile : output coordinates file (with extension .coil).
    • option :
      -withREF : if present, convert coordinates of REF-SENS and MEG-SENS channels. If omitted, only convert MEG-SENS channels.


  • Coil file format and examples
    • Coil file version 1
    • It is a text file with a .coil suffix. The informations are identified by keywords and values :
      diametre_coils : coil diameters (mm)
      nb_coils : number of coils
      nb_voies : number of channels
      # : comment(example : #channel 1 : A1)
      voieN : number of coils for channel N with N is the indice of the channel (starting from 1). For example : voie1 2 means 2 coils for channel 1.
      C_N_M : coordinates, orientation and weight of coil M of channel N. C_N_M is followed by Xcoil Ycoil Zcoil MXcoil MYcoil MZcoil WCoil with :
      Xcoil, Ycoil, Zcoil : coordinates of coil (mm) in head axis system.
      MXcoil, MYcoil, MZcoil : orientation of coil (mm). These values must be normalized.
      Wcoil : weight of coil.

      Download examples : exemple_bti.coil, exemple_ctf.coil, exemple_Neuromag.coil.

      Exemple_ctf.coil :

      diametre_coils 20.000000
      nb_coils 286
      nb_voies 143
      #voieN nb_coils
      #C_N_M Xcoil Ycoil Zcoil MXcoil MYcoil MZcoil PoidsCoil
      #N = channel indice, M = coil indice

      #voie 1 LC11
      voie1 2
      C_1_1 78.603996 81.996788 106.587189 -0.788269 -0.442448 -0.427636 1
      C_1_2 118.027443 104.124817 127.974411 0.788269 0.442448 0.427636 1

      #voie 2 LC12
      voie2 2
      C_2_1 85.594002 56.471432 114.443710 -0.858740 -0.263944 -0.439203 1
      C_2_2 128.541901 69.671989 136.409454 0.858740 0.263944 0.439203 1

      ……

      #voie 143 RP45
      voie143 2
      C_143_1 -17.488001 -79.049843 115.331032 0.154553 0.854542 -0.495853 1
      C_143_2 -25.217600 -121.787811 140.129990 -0.154553 -0.854542 0.495853 1

      Last modifications :
      - squid changed to coil : 05-07-1997 (Anne Cheylus, Olivier)
      - 1st version : 21-01-1997 (Anne, Olivier)

    • Coil file version 2
    • It is also a text file with a .coil suffix. The name of file must contain V2 to make difference with version 1. It is faster to read.
      As for version 1, the informations are identified by keywords and values :
      diametre_coils : coil diameters (mm)
      nb_coils : number of coils
      nb_voies : number of channels
      # : comment(example : #channel 1 : A1)
      voieN : number of coils for channel N (with N is the indice of the channel (starting from 1)), weight of each coil, indice of each coil. For example : voie1 2 1 -1 3 4 means 2 coils for channel 1 (coils 3 and 4), the weight of coils 3 and 4 are respectively 1 and -1. Channel 1 is the result of the difference of coil 3 minus coil 4.
      coil_data : matrix of coordinates and orientations of coils. Xcoil, Ycoil, Zcoil must be in mm. MXcoil, MYcoil, MZcoil must be normalize.
      Xcoil1 Ycoil1 Zcoil1 MXcoil1 MYcoil1 MZcoil1
      Xcoil2 Ycoil2 Zcoil2 MXcoil2 MYcoil2 MZcoil2
      XcoilN YcoilN ZcoilN MXcoilN MYcoilN MZcoilN
      Donwload example : ctf151_V2.coil.

      Last modifications :
      coils version 2 : march 2000 (Anne Cheylus)


  • Examples

  • Comments
  • ctf275_2coil creates version 1 coil file.

  • Current version
  • 1.02 24-06-2008

  • History
    • 1.01 (03-06-2008) : Prise en compte de la polarité des coils => Poids = -1 si ProperGain > 0
      1.02 (24-06-2008) : Suppression bug lecture du nom du fichier *.ds
      [modifier]
    • 1.01 03-06-2008 (MM) : use polarity of coils (weight=-1 if ProperGain > 0).
    • 1.02 24-06-2008 (MM) : bug fixe when reading name of ds directory.


  • File
  • $ELANPATH/bin/ctf275_2coil


  • See also
AttachmentSize
exemple_bti.coil5.95 KB
exemple_ctf.coil22.99 KB
exemple_Neuromag.coil23.38 KB