NAME

       sample1d - Resampling of 1-D data sets

SYNOPSIS

       sample1d infile [ -Fl|a|c ] [ -H[nrec] ] [ -Ixinc ] [ -M[flag] ] [ -Nknotfile ] [ -Sxstart
       ] [ -Tx-col] [ -V ] [ -bi[s][n] ] [ -bo[s][n] ]

DESCRIPTION

       sample1d reads a multi-column ASCII [or binary] data set from file [or standard input] and
       resamples  the  timeseries/profile  at locations where the user needs the values. The user
       must provide the column number of the independent (monotonically increasing or decreasing)
       variable.  Equidistant  or  arbitrary  sampling can be selected. All columns are resampled
       based on the new sampling interval.  Several interpolation schemes are available.

       infile This is a multi-column ASCII [of binary, see -b] file with  one  column  containing
              the  independent  variable  (which  must  be  monotonically in/de-creasing) and the
              remaining columns holding misc. data values.  If  no  file  is  provided,  sample1d
              reads from standard input.

OPTIONS

       No space between the option flag and the associated arguments.

       -F     Choose  from l (Linear), a (Akima spline), and c (natural cubic spline) [Default is
              -Fa].  You may change the default interpolant; see INTERPOLANT in your .gmtdefaults
              file.

       -H     Input  file(s)  has  Header  record(s).  Number of header records can be changed by
              editing your .gmtdefaults file. If used, GMT default is 1 header record.

       -I     xinc defines the sampling interval. [Default is the separation  between  the  first
              and second abcissa point in the infile]

       -M     Multiple  segment file. Segments are separated by a record whose first character is
              flag.  [Default is '>'].

       -N     knotfile is an optional ASCII file with the x locations where the data set will  be
              resampled in the first column

       -S     For  equidistant sampling, xstart indicates the location of the first output value.
              [Default is the smallest even multiple of xinc inside the range of infile]

       -T     Sets the column number of the independent variable [Default is 0 (first)].

       -V     Selects verbose mode, which will send progress  reports  to  stderr  [Default  runs
              "silently"].

       -bi    Selects  binary input. Append s for single precision [Default is double].  Append n
              for the number of columns in the binary file(s).  [Default is 2 (or  at  least  the
              number of columns implied by -T].

       -bo    Selects binary output. Append s for single precision [Default is double].

EXAMPLES

       To        resample        the        file       profiles.tdgmb,       which       contains
       (time,distance,gravity,magnetics,bathymetry) records, at 1km equidistant  intervals  using
       Akima's spline, try'

       sample1d profiles.tdgmb -I1 -Fa -T1 > profiles_equi_d.tdgmb

       To  resample the file depths.dt at positions listed in the file grav_pos.dg, using a cubic
       spline for the interpolation, try

       sample1d depths.dt -Ngrav_pos.dg -Fc > new_depths.dt

SEE ALSO

       gmt(1gmt), filter1d(1gmt)

                                            1 Jan 2004                                SAMPLE1D(l)