The covariance NMR can take few seconds for small data size, and can take 5 or 10 minutes for large data size.

In Varian and Bruker format, the number of points in w2 is set to 2048 if it is larger than 2048.

Please do not use w2 points more that 2048 in nmrPipe w2t1 and nmrPipe w2w1 format.

Input Format:

nmrPipe w2t1: one mixed time-frequency nmrPipe file.

nmrPipe w2w1: one 2D FT nmrPipe file.

Varian: a tar.gz file contains fid, procpar with correct phasing parameters along w2 (lp and rp)

Bruker: a tar.gz file contains ser, acqu*, pdata/1/proc* with correct phasing parameters along w2 (PHC0 and PHC1)

The data can be TPPI or States-TPPI.

The data can be homonuclear (like TOCSY or NOESY), or heteronuclear (like 1H-13C HSQC-TOCSY).

Method:

(regular) covariance NMR: can be applied to all of the above 4 formats.

indirect covariance NMR: can be applied only to nmrPipe w2w1 format.

w2 center frequency:

This is the xCAR value in nmrPipe.

It is used for Bruker and Varian format to reference w2 frequency axis.

water removal region:

This option allows the removal of spurious water (or an other strong) signal.

This is most beneficial in combination with indirect covariance NMR.

If the two ppm values are the same, no water is removed, i.e. this option is ignored.