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Remove duplicated rows using dplyr
...mple(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [3 x 3]
## Groups: x, y
##
## x y z
## 1 0 1 1
## 2 1 0 2
## 3 1 1 4
(In dplyr 0.2 you won't need...
搭建高可用mongodb集群（四）—— 分片 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...001
#使用admin数据库
use admin
#定义副本集配置
config = { _id:"shard1", members:[
{_id:0,host:"192.168.0.136:22001"},
{_id:1,host:"192.168.0.137:22001"},
{_id:2,host:"192.168.0.138:22001",arbiterOnly:true}
...
How do you convert a DataTable into a generic list?
...ET 3.5, you can use DataTableExtensions.AsEnumerable (an extension method) and then if you really need a List<DataRow> instead of just IEnumerable<DataRow> you can call Enumerable.ToList:
IEnumerable<DataRow> sequence = dt.AsEnumerable();
or
using System.Linq;
...
List<DataR...
Bootstrap Carousel image doesn't align properly
...better results for than the default height:500px
– CrandellWS
Jul 27 '15 at 23:08
You should do .carousel-inner > ....
How can I change the color of pagination dots of UIPageControl?
...
UPDATE:
This answer is 6 years old and very outdated, but it's still attracting votes and comments. Ever since iOS 6.0 you should be using the pageIndicatorTintColor and currentPageIndicatorTintColor properties on UIPageControl.
ORIGINAL ANSWER:
I ran into t...
get size of json object
i have a json object that gets returned by an AJAX request and I am having some trouble with the .length because it keeps returning undefined . Just wondering if I'm using it right:
...
quick random row selection in Postgres
... that contains couple of millions of rows. I have checked on the internet and I found the following
7 Answers
...
jQuery remove all list items from an unordered list
I forgot the jQuery command that will clear all list elements from a list. I did a bit of searching, done it a bunch of times before, but just simply forgot the command.
...
How can I resize an image dynamically with CSS as the browser width/height changes?
...
This can be done with pure CSS and does not even require media queries.
To make the images flexible, simply add max-width:100% and height:auto. Image max-width:100% and height:auto works in IE7, but not in IE8 (yes, another weird IE bug). To fix this, you...
how to set radio option checked onload with jQuery
...value='Male'>
<input type='radio' name='gender' value='Female'>
And you wanted to check the one with a value of "Male" onload if no radio is checked:
$(function() {
var $radios = $('input:radio[name=gender]');
if($radios.is(':checked') === false) {
$radios.filter('[value=...