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Applying a function to every row of a table using dplyr?
...yr 0.2 (I think) rowwise() is implemented, so the answer to this problem becomes:
iris %>%
rowwise() %>%
mutate(Max.Len= max(Sepal.Length,Petal.Length))
Non rowwise alternative
Five years (!) later this answer still gets a lot of traffic. Since it was given, rowwise is increasingly n...
“is” operator behaves unexpectedly with integers
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@WoodrowBarlow: The -5 is just a heuristic to capture common negative placeholders, I think. 0..255 covers arrays of single byte values. It’s 256 that’s mysterious, but I guess it’s for (dis)assembling integers into/from bytes.
– Davis Herring
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How do I make a Git commit in the past?
...d I found some old versions of a file already in the repository. How do I commit it to the history in the correct order according the file's "date modified" so I have an accurate history of the file?
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How do you Encrypt and Decrypt a PHP String?
...m advice in this answer.
Use libsodium if you have PECL access (or sodium_compat if you want libsodium without PECL); otherwise...
Use defuse/php-encryption; don't roll your own cryptography!
Both of the libraries linked above make it easy and painless to implement authenticated encryption into you...
From inside of a Docker container, how do I connect to the localhost of the machine?
...ould land in Docker 20.04
TLDR
Use --network="host" in your docker run command, then 127.0.0.1 in your docker container will point to your docker host.
Note: This mode only works on Docker for Linux, per the documentation.
Note on docker container networking modes
Docker offers different ne...
Database, Table and Column Naming Conventions? [closed]
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I recommend checking out Microsoft's SQL Server sample databases:
https://github.com/Microsoft/sql-server-samples/releases/tag/adventureworks
The AdventureWorks sample uses a very clear and consistent naming convention that uses...
List changes unexpectedly after assignment. How do I clone or copy it to prevent this?
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What is 'Context' on Android?
...new SimpleCursorAdapter(getApplicationContext(), ...);
Accessing standard common resources:
Services like LAYOUT_INFLATER_SERVICE, SharedPreferences:
context.getSystemService(LAYOUT_INFLATER_SERVICE)
getApplicationContext().getSharedPreferences(*name*, *mode*);
Accessing components implicitly:
Re...
Cocoa: What's the difference between the frame and the bounds?
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An operation on a socket could not be performed because the system lac...
...口可以重复使用。
参考：https://support.microsoft.com/zh-cn/help/196271/when-you-try-to-connect-from-tcp-ports-greater-than-5000-you-receive-t