sample1d - Resampling of 1-D data sets
sample1d infile [ -Fl|a|c ] [ -H[nrec] ] [ -Ixinc ] [ -M[flag] ] [
-Nknotfile ] [ -Sxstart ] [ -Tx-col] [ -bi[s][n] ] [ -bo[s] ]
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.
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
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
-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
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
Man(1) output converted with