问未定义的ReferenceError：$是未定义的- Rails

EN

Uncaught ReferenceError: $ is not defined

var _PremiumApiBaseURL = 'http://api.worldweatheronline.com/premium/v1/';
var _PremiumApiKey = 'APIKEY';

//Get Marine Weather Data
function JSONP_MarineWeather(input) {
var url = _PremiumApiBaseURL + "marine.ashx?q=" + input.query +
                               "&format=" + input.format +
                               "&fx=" + input.fx +
                               "&key=" + _PremiumApiKey +
                               "&tide=yes&";

jsonP(url, input.callback);
}

// Helper
function jsonP(url, callback) {
$.ajax({
    type: 'GET',
    url: url,
    async: false,
    contentType: "application/json",
    jsonpCallback: callback,
    dataType: 'jsonp',
    success: function (json) {
        console.dir('success');
    },
    error: function (e) {
        console.log(e.message);
    }
});
}



var resultContainer = $('#resultContainer');
var output = '';


$(document).ready(function () {
  GetMarineWeather();
});


function GetMarineWeather(e) {
    var marineWeatherInput = {
      query: '26.13,-80.10',
      format: 'JSON',
      fx: '',
      callback: 'MarineWeatherCallback'
     };
    JSONP_MarineWeather(marineWeatherInput);
    e.preventDefault();
}



function MarineWeatherCallback(marineWeather) {
    var allDataToday = marineWeather.data.weather[0]
    output = "<br/> Date: " + allDataToday.date;
    output += "<br/> Min Temp (f): " + allDataToday.mintempF;
    output += " - Max Temp (f): " + allDataToday.maxtempF;
    output += "<br/>";
    //6AM
    output += "<br/> Time: 6AM";
    output += " - Surf: " + allDataToday.hourly[2].swellHeight_ft + "ft";
    output += " - Swell: " + allDataToday.hourly[2].swellDir16Point + " " + allDataToday.hourly[2].swellPeriod_secs + "sec";

    resultContainer.empty();
    resultContainer.html(output);
}