oopus, Author at Oopus Blog

在 node.js 的基础教程里面，一开始总是会教大家来写 server.js

绝大多数情况下，这个例子会让大家觉得“yeah，写服务器好简单”。但是在某些 linux 虚拟主机下，这个简单的例子会无法实现。

其实原因非常简单，防火墙过滤掉了 createServer 的 listen 端口。

这时候只要把 listen 端口绑在常用的

June 17, 2017

change time zone in Debian

dpkg-reconfigure tzdata

June 13, 2015

The only corrected tutorial of connecting points to lines in CartoDB

https://groups.google.com/forum/#!msg/cartodb/PHKbPWKvMmc/NKe18KSt-pUJ

Hi Amanda,

Are you doing the tutorial but with your own data? Did you get the tutorial to work just on its own first? It might help to run through it as is first so you can get a hang of what it does.

To do it with the table map_1, I would just run this query,

SELECT 0 as cartodb_id, ST_MakeLine(the_geom_webmercator) the_geom_webmercator FROM map_1

UNION ALL

SELECT cartodb_id, the_geom_webmercator FROM map_1

The first half (before the UNION) makes a line from all your points. The second (after the UNION), just selects the points as is.

Next, on your map you are probably only going to see points. That is because there is no style set for drawing a line. So I would use the following CSS,

#map_1 {

//points

[mapnik-geometry-type=point] {

marker-fill: #FF6600;

marker-opacity: 1;

marker-width: 12;

marker-line-color: white;

marker-line-width: 3;

marker-line-opacity: 0.9;

marker-placement: point;

marker-type: ellipse;marker-allow-overlap: true;

}