At present, Wit!P can only read crosspeak files in Felix [1] Peak File format (default file extension: .xpk), and write crosspeak files in Felix or Sparky [2] format (default extension: .xpk). In Wit!P crosspeak lists are associated with a spectrum, and may be read into the program by the NMR spectrum command
spectrum> peaks read foobar.mat unassigned.xpk(to read the peak list unassigned.xpk and associate it with the spectrum foobar.mat, which must be a spectrum which was opened with the spectrum open command).
The Felix Peak File format is a fixed format text file, with a two line header, followed by one line per crosspeak. The first header is a comment, which is arbitrary, except that the first three characters must be c**. The second header line contains the 3 letter tag xpk in columns 1-3, followed by the dimension of the spectrum (columns 4-11, right-justified). Crosspeak records contain the following information (example for a 3-dimensional spectrum):
nr s1 w1 f1 ass1
s2 w2 f2 ass2 s3
w3 f3 ass3 z
(I6, 3(F10.3,F10.3,I6,2X,A16), F10.2)
nr:
|
Peak number, in ascending order, not necessarily contiguous |
si:
|
Peak position in points, i-th dimension (i = 1...3) |
wi:
|
Peak width in points, i-th dimension (i = 1...3) |
fi:
|
unknown content (i = 1...3) |
assi:
|
assignment field, i-th dimension (i = 1...3) |
z:
|
unknown content |
Peak lists may be written to disk files in Felix or Sparky format with the NMR spectrum command, e.g.
spectrum> peaks write foobar.mat felix assigned.xpk(to write the peaks associated with spectrum foobar.mat in Felix format to the disk file assigned.xpk). On output, the InSane procedure uses the following conventions for the assignment fields assi:
References:
1. http://www.accelrys.com/felix. Commercial NMR data processing, visualization and analysis software from Accelrys.
2. http://www.cgl/ucsf/edu/home/sparky. Sparky is a graphical NMR assignment and integration program for proteins, nucleic acids and other polymers, written by T.D.Goddard and D.G.Kneller, University of California, San Francisco.