大约有 47,000 项符合查询结果（耗时：0.0470秒） [XML]
Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...similar questions scattered around this site.
tmp <- data.frame(x=gl(2,3, labels=letters[24:25]),
y=gl(3,1,6, labels=letters[1:3]),
z=c(1,2,3,3,3,2))
Using the tidyverse:
The new cool new way to do this is with pivot_wider from tidyr 1.0.0. It returns a d...
How do I use floating-point division in bash?
...d
– Nahuel Fouilleul
Oct 4 '12 at 7:32
4
...
Get the cartesian product of a series of lists?
...
13 Answers
13
Active
...
Regular expression to match standard 10 digit phone number
...
^(\+\d{1,2}\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
Matches the following
123-456-7890
(123) 456-7890
123 456 7890
123.456.7890
+91 (123) 456-7890
If you do not want a match on non-US numbers use
^(\+0?1\s)?\(?\d{3}\)?[\s.-]\d{3}[\s.-]\d{4}$
...
Sample random rows in dataframe
...rnorm(20), nrow=10))
> df
X1 X2
1 0.7091409 -1.4061361
2 -1.1334614 -0.1973846
3 2.3343391 -0.4385071
4 -0.9040278 -0.6593677
5 0.4180331 -1.2592415
6 0.7572246 -0.5463655
7 -0.8996483 0.4231117
8 -1.0356774 -0.1640883
9 -0.3983045 0.7157506
10 -0.9060305 2.3234...
how to change default python version?
I have installed python 3.2 in my mac. After I run /Applications/Python 3.2/Update Shell Profile.command , it's confusing that when I type python -V in Terminal it says that Python 2.6.1 , how can I change the default python version?
...
Sublime Text 3能用支持的插件推荐 - 更多技术 - 清泛网 - 专注C/C++及内核技术
Sublime Text 3能用支持的插件推荐从二月份用测试版本build 3012开始用sublime text 3，虽然很多插件在sublime text 3不工作了，因为sublime text 3修复了2的一些bug...
二月份用测试版本build 3012开始用sublime text 3，虽然很多插件在sublime text 3不...
Apply a function to every row of a matrix or a data frame
...
You simply use the apply() function:
R> M <- matrix(1:6, nrow=3, byrow=TRUE)
R> M
[,1] [,2]
[1,] 1 2
[2,] 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extr...
Eclipse RCP Plug-in开发自学教程（Eclipse3.6） - 文档下载 - 清泛网 - ...
Eclipse RCP Plug-in开发自学教程（Eclipse3.6） Eclipse RCP Plug-in本教程素材来源于网络，经过本人的整理、添加以及部分的重写，将原有的Eclipse3.3版本的一些内容完全迁移到Eclipse3.6版本上来。基于开源以...本教程素材来源于网络，经...
How do I sort one vector based on values of another
... |
edited Oct 15 '09 at 0:31
answered Oct 14 '09 at 21:47
I...