 height (hs)
      c.) wave direction
      d.) mesh
      e.) peak period
      f.) U10
      g.) V10
      h.) bottom orbital velocity
      i.) bottom period
      j.) H/h ratio
      k.) wave-induced bed stress

 EXAMPLE USAGE
   swan2netcdf('gom1.mat','gom1.nc','gom1','20070101_000000','20070131_000000',3600,true,.045)
     this converts gom1.mat to gom1.nc using SWAN grid files gom1.ele, gom1.bot
     and gom1.node from Jan 1, 2007 00:00:00 to Jan 31, 2007 00:00:00 in increments
     of 1 hour.

 NOTE