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Group by multiple columns in dplyr, using string vector input
...oup_by_at(vars(one_of(columns))) %>%
summarize(Value = mean(value))
#compare plyr for reference
df2 <- plyr::ddply(data, columns, plyr::summarize, value=mean(value))
table(df1 == df2, useNA = 'ifany')
## TRUE
## 27
The output from your example question is as expected (see comparison to...
How to convert CharSequence to String?
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@TheOnlyAnil, maybe you should ask that as a question. Comments on an answer to a tangentially related question are not a good place to try and tease out your requirements.
– Mike Samuel
May 5 '15 at 14:38
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How can I initialize base class member variables in derived class constructor?
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manish srivastavamanish srivastava
2911 bronze badge
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How to sleep for five seconds in a batch file/cmd [duplicate]
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One hack is to (mis)use the ping command:
ping 127.0.0.1 -n 6 > nul
Explanation:
ping is a system utility that sends ping requests. ping is available on all versions of Windows.
127.0.0.1 is the IP address of localhost. This IP address is guaranteed ...
Android Studio: how to attach Android SDK sources?
...me.
diff --git a/options/jdk.table.xml b/options/jdk.table.xml
index 0112b91..33828b8 100644
--- a/options/jdk.table.xml
+++ b/options/jdk.table.xml
@@ -76,7 +76,7 @@
</javadocPath>
<sourcePath>
<root type="composite">
- <root type="simpl...
Showing Travis build status in GitHub repo
I remember recently seeing the Travis build status of a pr or commit in GitHub browsing the repository (but can't find where). I'm not talking about the Travis build status images in README.md but an actual GitHub feature (green box with a friendly check mark).
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Getting the index of the returned max or min item using max()/min() on a list
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91
@Kashyap It's actually O(N), not O(N^2). In the min case, first min(values) is evaluated, which is O(N), then values.index() is called, wh...
DbEntityValidationException - How can I easily tell what caused the error?
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Leniel Maccaferri
91.3k4040 gold badges331331 silver badges445445 bronze badges
answered Apr 4 '13 at 19:54
Martin Devi...
Stop and Start a service via batch or cmd file?
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Use the SC (service control) command, it gives you a lot more options than just start & stop.
DESCRIPTION:
SC is a command line program used for communicating with the
NT Service Controller and services.
USAGE:
sc <...
How to exclude specific folders or files from validation in Eclipse?
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