NAN value and computing angle in equatorial plane with great

I am developping a small code with which I need to compute the difference of angles in equatorial plane (ie the difference of longitudes) as a function of the angles difference in a great circle plane (parameterized by a given latitude). I used the following formula from this wikipedia link : d(sigma) = arcos (sin(phi1).sin(phi2) + cos(phi1).cos(phi2).cos(d(lambda)) The goal is to compute d(l

NAN值和赤道平面上的计算角度很大

我正在开发一个小代码,我需要根据大圆平面(由给定的纬度参数化)中的角度差来计算赤道平面中角度的差异(即经度差异)。 我从这个维基百科链接使用了以下公式: d(sigma) = arcos (sin(phi1).sin(phi2) + cos(phi1).cos(phi2).cos(d(lambda)) 目标是计算d(lambda)的角度差。 在我的代码中,输入参数是: radius = 50 phi1 = 0 phi2 = initial latitude describe below d(sigma) = (distance / theta) where theta is the

Where are variables in a closure stored

Like the following codes: var foo = function() { var a = 1; // closure var return function() { // closure fun console.log(a); } }; var bar = foo(); When foo exits(or say, returns), we know that the variable a will not be destroyed and remains in memory(that's why closure works). So my problem is where does the the variable a store, stack or heap? A closure is just an

封闭中的变量存储在哪里

像下面的代码一样: var foo = function() { var a = 1; // closure var return function() { // closure fun console.log(a); } }; var bar = foo(); 当foo退出(或者说退货)时,我们知道变量a不会被销毁并保留在内存中(这就是闭包的原因)。 所以我的问题是变量是商店,堆栈还是堆? 封闭只是堆栈概念的演变。 当调用函数时,堆栈用于分隔/隔离范围。 当一个函数返回堆栈帧(激活记录)时,弹出

Select all the text in an input, focusin

I want to have all the text selected when I give the focus to an element. I used $('.class-focusin').focusin(function(e) { $(this).select(); }); But it's not the perfect behavior I want. When i click between two characters, the input value is not seleted, there is a cursor in the middle. I want the behavior of the url bar in chrome browser: you click and the cursor is replaced by th

选择输入中的所有文本,focusin

当我将焦点放在元素上时,我想要选择所有文本。 我用了 $('.class-focusin').focusin(function(e) { $(this).select(); }); 但这不是我想要的完美行为。 当我在两个字符之间单击时,输入值不被选择,中间有一个光标。 我想要在Chrome浏览器中使用url栏的行为:单击并将光标替换为值选择 随意在这个小提琴中测试我的问题:http://jsfiddle.net/XS6s2/8/ 我希望文本一旦被选中就能够接收光标。 答案选择,下面肯定

Meteor Animation

I am trying to implement an animation where an item animates to the left after it gets selected. The following code works. But only about 80% of the time. JS //myItem Template.myItem.rendered = function(){ if(Session.get("selected_item") === this.data._id){ $(this.firstNode).addClass("selected"); } else { $(this.firstNode).removeClass("selected"); } }; Template.myItem.events({

流星动画

我试图实现一个动画,其中一个项目在被选中后向左移动。 以下代码有效。 但只有大约80%的时间。 JS //myItem Template.myItem.rendered = function(){ if(Session.get("selected_item") === this.data._id){ $(this.firstNode).addClass("selected"); } else { $(this.firstNode).removeClass("selected"); } }; Template.myItem.events({ "click .myItem": function(evt, template){ Session.set("se

Pie chart click issue

Ive been trying to create a graph to display events occuring in different regions of the world. so I basically went for a combination of two graph 1) d3 google graph (http://bl.ocks.org/mbostock/899711) to show the regions via map and jquery flot pie charts ( http://people.iola.dk/olau/flot/examples/pie.html) to map the events. Ive stored all the corresponding lattitiude longitude values in to

饼图点击问题

我一直试图创建一个图表来显示在世界不同地区发生的事件。 所以我基本上结合了两个图1)d3谷歌图(http://bl.ocks.org/mbostock/899711)通过地图和jquery flot饼图来显示区域(http://people.iola。 dk / olau / flot / examples / pie.html)来映射事件。 我将所有对应的经纬度值存储在一个数组中,并在这些值的基础上附加地图上的标记。 所以基本上我会在<foriegnobject>的帮助下在相应标记上创建一个xhtml:div空间

Javascript namespacing convention

wI'm unsure which is the better namespace convention to use. var App = {}; // global variable, the root of our namespace (function() { App.something = function() { } })(); or (function() { window.App = {}; //global variable, the root of our namespace App.something = function() { } })(); window.App and var App are both global variables so both conventions achieve the

Javascript命名空间约定

我不确定哪个是更好的命名空间惯例使用。 var App = {}; // global variable, the root of our namespace (function() { App.something = function() { } })(); 要么 (function() { window.App = {}; //global variable, the root of our namespace App.something = function() { } })(); window.App和var App都是全局变量,所以两个约定都达到相同的结果,但哪个更好? 唯一的区别是,在第一个变体

Detect if device is iOS

I'm wondering if it's possible to detect whether a browser is running on iOS, similar to how you can feature detect with Modernizr (although this is obviously device detection rather than feature detection). Normally I would favour feature detection instead, but I need to find out whether a device is iOS because of the way they handle videos as per this question YouTube API not working

检测设备是否为iOS

我想知道是否可以检测浏览器是否在iOS上运行,类似于可以使用Modernizr进行功能检测的功能(尽管这显然是设备检测而不是功能检测)。 通常情况下,我会倾向使用功能检测,但是我需要找出设备是否是iOS,因为它们处理视频的方式与此问题相同YouTube API不支持iPad / iPhone /非Flash设备 检测iOS 我不是用户代理嗅探的粉丝,但这里是你如何做的: var iOS = /iPad|iPhone|iPod/.test(navigator.userAgent) && !wind

How to determine if the client is a touch device

This question already has an answer here: What's the best way to detect a 'touch screen' device using JavaScript? 34 answers You can use the following JS function: function isTouchDevice() { var el = document.createElement('div'); el.setAttribute('ongesturestart', 'return;'); // or try "ontouchstart" return typeof el.ongesturestart === "function"; } Source: Detecting t

如何确定客户端是否是触摸设备

这个问题在这里已经有了答案: 使用JavaScript检测“触摸屏”设备的最佳方式是什么? 34个答案 你可以使用下面的JS函数: function isTouchDevice() { var el = document.createElement('div'); el.setAttribute('ongesturestart', 'return;'); // or try "ontouchstart" return typeof el.ongesturestart === "function"; } 来源:检测基于触摸的浏览。 请注意,上述代码仅测试浏览器是否支持触摸,而不是设备

How to close javascript dropdown menu by clicking anywhere?

This question already has an answer here: How do I detect a click outside an element? 76 answers 尝试下面的代码,它应该工作$(document).click(function(event) { if(!$(event.target).closest('#myDropdown').length) { if($('#myDropdown').is(":visible")) { $('#myDropdown').hide() } } }) 您可以使用此代码: - var dropdown = $('dropdown_selector'); $(documen

如何通过点击任何地方关闭javascript下拉菜单?

这个问题在这里已经有了答案: 如何检测元素外的点击? 76个答案 尝试下面的代码,它应该工作$(document).click(function(event) { if(!$(event.target).closest('#myDropdown').length) { if($('#myDropdown').is(":visible")) { $('#myDropdown').hide() } } }) 您可以使用此代码: - var dropdown = $('dropdown_selector'); $(document).click(function(e){ if(e.target ==

Jquery div to open/close hidden div properly

This question already has an answer here: How do I detect a click outside an element? 76 answers $(document).click(function (eventObj) { if (eventObj.target.id != "help-icon") { $("#help-menu").hide(); } else { $("#help-menu").toggle(); } }); 编辑:如果你想单击出现的div而不会再隐藏它: $(document).click(function(eventObj) { if (eventObj.target.id == "help-icon"

jquery div正确地打开/关闭隐藏的div

这个问题在这里已经有了答案: 如何检测元素外的点击? 76个答案 $(document).click(function (eventObj) { if (eventObj.target.id != "help-icon") { $("#help-menu").hide(); } else { $("#help-menu").toggle(); } }); 编辑:如果你想单击出现的div而不会再隐藏它: $(document).click(function(eventObj) { if (eventObj.target.id == "help-icon") { $("#help-menu").toggle()