【求助】请教??? Attempt to execute SCRIPT ezplot as a function
 

请教大侠:在MATLAB中有的内部命令提示下面错误,而书中就是直接这样调用,请问这种问题该怎么解决??谢谢!
>> ezplot('x^3+y^3-5*x*y+1/5')
??? Attempt to execute SCRIPT ezplot as a function.