• then, specifying the title to
    mytitle= "Skagerak circulation"
    
  • further, modifying the contents of four lines near the top to
    x1= 50     ; Leftmost  grid point to depict, for dimension  x  or  lon
    x2=150     ; Rightmost grid point to depict
    y1= 45     ; Lowermost grid point to depict, for dimension  y  or  lat
    y2=120     ; Uppermost grid point to depict
    
    in order to zoom in
  • and modifying the vector specification further down to
    vsz= 0.04   ; Size (length) of reference vector
    vsp= 0.20   ; Speed         of reference vector
    vd = 0.04   ; Distance between vectors
    curly_on= 1 ; =1: Use curly vectors, otherwise, use standard vectors
    
  • Finally, the following command was issued:

    mvector.sh 4d bio4km_uv.nc u v 1 1 43 -25

    By executing this command, a set of ppm & gif images for time step no. 1 through 43 results. When the gif images assembled as an animation, the result is:


    mvector.sh: syntax

    mvector.sh --help
    
            mvector.sh  /  ncl-metno 1.2
    
    >>>
    >>>
    >>> Syntax:
    >>> =======
    >>>
    >>> NOTE: This script will provide a set of output files, where
    >>>  the value of the final (3rd or 4th) dimension changes from
    >>>  one output file to the next. Below, we assume that this
    >>>  dimension is time.
    >>>
    >>> ...if  <option> is  4d  or  4dmap:
    >>>  mvector.sh <option> <file> <u> <v> <depth> <first> <last> (<step>)
    >>> ...if  <option> is  3d  or  3dmap:
    >>>  mvector.sh <option> <file> <u> <v> <first> <last> (<step>)
    >>> where
    >>>    <option>    specifies dimensions and geo- or nongeo-grid
    >>>                 implemented:
    >>>                  [34]d    - [34]D fields
    >>>                  [34]dmap - [34]D fields, dims. are lon & lat
    >>>                  ...[34]dmap will be displayed on a geogr. map
    >>>    <file>      name of the netcdf file
    >>>    <u>         name of variable w/ velocity in the x-direction
    >>>                 on the netcdf file (case sensitive)
    >>>    <v>         name of variable w/ velocity in the y-direction
    >>>                 on the netcdf file (case sensitive)
    >>>    <depth>     vertical level no.
    >>>    <first>     first time step no.
    >>>    <last>      last  time step no.
    >>>    <step>      time step between consequtive frames
    >>>                 (optional, set to  1  if not specified by user)
    >>>    <delay>     frame delay in ms (optional, set to  10  if not specified by user)
    >>>
    >>>  The script will produce a gif animation.
    >>>
    >>>
    >>> User specifications:
    >>> ====================
    >>>
    >>>  By copying the default spec.s from