def set ( var, value = "" )
      value = "\"#{value}\"" if QUOTED.include? var unless value =~ /^'.*'$/
      @settings << [ :set, var, value ]
    end
def set ( var, value = "" )
      value = "\"#{value}\"" if QUOTED.include? var unless value =~ /^'.*'$/
      @settings << [ :set, var, value ]
    end
Set a variable to the given value.  +Var+ must be a gnuplot variable and
 +value+ must be the value to set it to.  Automatic quoting will be
 performed if the variable requires it.

 This is overloaded by the +method_missing+ method so see that for more
 readable code.