MB-System Unix Manual Page: mbstripnan

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    mbstripNaN
    Section:  MB-System 5.0  (1)
    Updated:  26 October 2009
    Index

    NAME

    mbstripNaN - filter to remove NaN nodes

    VERSION

    Version 5.0

    SYNOPSIS

    mbstripNaN

    DESCRIPTION

    mbstripNaN is a utility for removing NaN nodes that are produced
    by the GMT utilities grd2xyz and blockmean with the -bo
    option.  The standard output
    of mbstripNaN may be fed into the standard input of surface with
    the -bi option.  This is used by the mbm_grd2geovrml utility in
    order to spline fill areas of no data so that irregular bathymetry may
    be effectively visualized using GeoVRML which has no concept of NaN.

    Note that mbstripNaN works with a double precision data stream.

    The code is simple.  Here it is:

      #include <stdio.h>

      #include <math.h>

      /*

       * Read double x,y,z on stdin and send to stdout all

       * triplets but ones where z == NaN

       */

      main () {

              struct node { double lon, lat, height; };

              struct node n;

              while ( ( fread(&n, 24, 1, stdin) > 0 ) ) {

                      if ( ! isnan(n.height) ) {

                              fwrite(&n, 24, 1, stdout);

                      }

              }

       }

    EXAMPLE

    This is a command that mbm_grd2geovrml constructs and executes:

      #

      # Convert grid to xyz format for filling in blank

      # areas, preprocess w/blockmean, use surface to

      # extrapolate to no data areas

      #

      grd2xyz -bo Samp_OregonMarginI_bath.grd | blockmean \

        -bi -bo -V -I0.00336363636363635/0.00134545454545457 \

        -R-125.2/-124.867/45/45.1332 | mbstripNaN | surface \

        -bi -I0.00336363636363635/0.00134545454545457 \

        -S0.333312 -T0.35 -GTmp_OregonMarginI_bath.grd -V \

        -R-125.2/-124.867/45/45.1332

    SEE ALSO

    grd2xyz(1),
    blockmean(1),
    surface(1),
    mbm_grd2geovrml(1)

    BUGS

    How many bugs can there be in an 8 line program?

     Index

    NAME
    VERSION
    SYNOPSIS
    DESCRIPTION
    EXAMPLE
    SEE ALSO
    BUGS

Last Updated: 26 October 2009

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