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)