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Combine two or more columns in a dataframe into a new column with a new name
... already mentioned in comments by Uwe and UseR, a general solution in the tidyverse format would be to use the command unite:
library(tidyverse)
n = c(2, 3, 5)
s = c("aa", "bb", "cc")
b = c(TRUE, FALSE, TRUE)
df = data.frame(n, s, b) %>%
unite(x, c(n, s), sep = " ", remove = FALSE)
...
Google Tag Manager 入门指南 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...于是又添加了如下的代码：
_gaq.push(
["_addOrganic", "baidu", "word"],
["_addOrganic", "so.360.cn", "q"],
["_addOrganic", "sogou", "query"],
["_addOrganic", "soso", "w"],
["_addOrganic", "gougou", "search"],
["_addOrganic", "youdao", "q"]
);
随着对业务分析的深...
Can I Install Laravel without using Composer?
... Unfortunately, many of my clients are on shared hosting that does not provide it, and I did not think that it would work. Can updates be performed using commands from a PHP script?
– Mike Rockétt
Apr 11 '13 at 5:47
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Video auto play is not working in Safari and Chrome desktop browser
I spent quite a lot of time trying to figure out why video embedded like here:
21 Answers
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Can I avoid the native fullscreen video player with HTML5 on iPhone or android?
... JavaScript code that renders other content synchronized with the running video. It works great in desktop browsers: Firefox, Chrome, and Safari. On an iPhone or a DroidX, the native video player pops up and takes over the screen, thus obscuring the other dynamic content that I want to display simul...
How can I add a class to a DOM element in JavaScript?
...n attribute, you can assign any string you like, even if it makes for invalid html
– Darko Z
Apr 29 '14 at 9:47
18
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How do I check if a file exists in Java?
...n issue with stale file handles: bugs.java.com/bugdatabase/view_bug.do?bug_id=5003595 It's kind of obscure, but has been the cause of some frustrating bugs in production code before.
– CAW
Mar 17 '17 at 22:17
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Coarse-grained vs fine-grained
...ion or observation. It is the
extent to which a larger entity is
subdivided. For example, a yard broken
into inches has finer granularity than
a yard broken into feet.
Coarse-grained systems consist of
fewer, larger components than
fine-grained systems; a coarse-grained
descriptio...
TypeScript with KnockoutJS
...is why we use definition files for code written in JavaScript so as to provide typescript type checking. Of course you could declare libs as "any", but this is not good.hope I helped!
– George Mavritsakis
Dec 1 '12 at 16:03
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How to input a regex in string.replace?
...ed (i.e. with a backslash placed in front - and the rules are different inside and outside character classes.) There is an excellent online tutorial at: www.regular-expressions.info. The time you spend there will pay for itself many times over. Happy regexing!
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