NMRPipe Processing Functions
LS: Left Shift and Zero Pad.

LS applies a leftshift to the points in each vector from the current dimension of the data. The shifted points at the start of the data vector are replaced with zeros. For example, if an 8point data vector consists of the following values:
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0then after a 2point leftshift (
LS ls 2
) the result
will be:
3.0 4.0 5.0 6.0 7.0 8.0 0.0 0.0
The LS function will only shift by an integer number of points; for shifting data by a fractional number of points, use the FSH function.
OPTIONS
rs rsVal
Specifies the number of points for the shift. If the number is
positive, the data will be shifted to the right. If it is negative,
the data will be shifted to the left.
This value can also be specified with spectral units (% Hz ppm).
In these cases, the amount of shift requested will be rounded
to the nearest integer.
sw
If this flag is used with timedomain data, the recorded
timedomain sizes NDAPOD and NDTDSIZE are adjusted by
the number of points shifted. If this flag is used with
frequencydomain data, the chemical shift calibration
information is updated (NDORIG and NDCENTER).
EXAMPLES
The following, when applied in the timedomain, is equivalent to applying a first order phase of P1=360 in the frequency domain; applying the zerofill before the LS avoids losing one point:
 nmrPipe fn ZF auto \  nmrPipe fn LS rs 1 \
SEE ALSO
Shifting functions
RS (rightshift, integer number of points)
CS (circularshift, integer number of points)
FSH (circularshift, fractional number of points)
and phasecorrection function
PS which can be used to apply the equivalent
of a circular shift in one domain by applying a first order phase
correction in the other domain.