, with the contents of three lines changed to
    </p>
    <pre>v1=  1.   ; Low  value for isopleths, disregarded when  nv  is 0 or 1
v2= 18.   ; High value for isopleths, disregarded when  nv  is 0 or 1
nv= 17    ; No. of isopleths, there will be  nv+1  colors
</pre>
    <p>
      in order to specify the use of contours and colors.
    </p>

    <img src="./tempmask_col.png" width="343" height="258" />


    <h3><a name="syntax_c-mask">c-mask.sh</a>: syntax</h3>


<pre>marine:~% c-mask.sh --help

           c-mask.sh  /  ncl-metno 1.2

>>>
>>>
>>> Syntax:
>>> =======
>>>
>>>  c-mask.sh &lt;option> &lt;file1> &lt;file2> &lt;var1> &lt;var2> &lt;val1> &lt;val2> [&lt;d3node> (&lt;d4node>)]
>>> where
>>>    &lt;option>  specifies dimensions and geo- or nongeo-grid
>>>                  [234]d               - [234]D fields
>>>                  [234]dmap/[234]dmapr - [234]D fields, dims. are lon &amp; lat
>>>                  [234]dMap/[234]dMapr - [234]D fields, lon &amp; lat are 2d fields
>>>                  ...[234]d[mM]ap will be displayed on a geogr. map
>>>                  options *r mask values inside the range [&lt;val1>,&lt;val2>],
>>>                   other options mask values outside of the range
>>>    &lt;file1>   name of the netcdf file w/ variable to depict
>>>    &lt;file2>   name of the netcdf file w/ masking variable
>>>               you may type '.' if &lt;file1> & &lt;file2> are the same
>>>    &lt;var1>    name of variable on the netcdf file to depict
>>>               (case sensitive)
>>>           NOTE! This script requires the existence of an
>>>                 attribute 'missing_value' to &lt;var1>
>>>    &lt;var2>    name of variable to use for masking &lt;var1>
>>>               (case sensitive)
>>>               you may type '.' if &lt;var1> & &lt;var2> are the same
>>>    &lt;val1>, &lt;val2>
>>>              limits for masking:
>>>               &lt;option> = *r  :
>>>                   &lt;var1> will be masked for values  INSIDE the range (&lt;val1>,&lt;val2>)
>>>               otherwise      :
>>>                   &lt;var1> will be masked for values OUTSIDE the range (&lt;val1>,&lt;val2>)
>>>    &lt;d3node>  node no. of third dimension
>>>                if &lt;option> is one of   2d(r), 2dmap(r)
>>>                  and a fourth argument is present
>>>                  or if &lt;option> is negative,
>>>                 this will be interpreted as a flag that will cause
>>>                  the ncl script to remain (see examples below)
>>>    &lt;d4node>  node no. of fourth dimension
>>>
>>>  Special case:
>>>   If &lt;option> is one of [234]dMap, the name of the 2d longitude and
>>>    latitude variable may be specified on the command line:
>>>   c-mask.sh &lt;option> &lt;lonname> &lt;latname> &lt;file1> &lt;file2> &lt;var1> &lt;var2> &lt;val1> &lt;val2> [&lt;d3node> (&lt;d4node>)]
>>>    (Alternatively, if these names are not 'lon' or 'lat', 'userdef.ncl' may
>>>     be edited when option is one of [234]dMap.)
>>>
>>>  The script will produce an eps-file and a png-file.
>>>
>>>
>>> User specifications:
>>> ====================
>>>
>>>  By copying the default spec.s from