Function panda_parse_double_opt 

pub unsafe extern "C" fn panda_parse_double_opt(
    args: *mut panda_arg_list,
    argname: *const i8,
    defval: f64,
    help: *const i8,
) -> f64

panda_parse_double_opt() - Get optional value corresponding to this plugin arg as a double. @args: The previously parsed panda_arg_list. @argname: The name of the argument in args. @defval: A default value. @help: Help text.

Look through the arguments in args, and if any have name argname, translate the associated value into a double and return it. If no such name is found, use the default.

Return: a double from args.