sample1d

       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] ]

DESCRIPTION

       sample1d  reads  a multi-column ASCII [or binary] data set
       from file [or standard  input]  and  resamples  the  time­
       series/profile  at locations where the user needs the val­
       ues. The user must provide the column number of the  inde­
       pendent (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-creas­
              ing)  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 argu­
       ments.

       -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 .gmt­
              defaults  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 loca­
              tions  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

       -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  preci­
              sion [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   >   pro­
       files_equi_d.tdgmb

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

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

SEE ALSO

       gmt(l), filter1d(l)