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How to drop columns by name in a data frame
... null_assign(dtest, drop_vec) 74.593 83.0585 86.2025 94.0035 1476.150
subset(dtest, select = !names(dtest) %in% drop_vec) 106.280 115.4810 120.3435 131.4665 65133.780
subset(dtest, select = names(dtest)[!names(dtest) %in% drop_vec]) 108.611 119.4830 124.0...
Difference Between One-to-Many, Many-to-One and Many-to-Many?
...address_2_id and address_3_id or a look up table with unique constraint on user_id and address_id.
In unidirectional, a User will have Address address. Bidirectional
will have an additional List<User> users in the Address class.
In Many-to-Many members of each party can hold reference to a...
SVG: text inside rect
...ently many other people came here for D3
– cosmichero2025
May 18 '18 at 19:11
1
Is it possible to...
Many-to-many relationship with the same model in rails?
... information.
TL;DR
# user.rb
has_many :friendships, :foreign_key => "user_id", :dependent => :destroy
has_many :occurances_as_friend, :class_name => "Friendship", :foreign_key => "friend_id", :dependent => :destroy
..
# friendship.rb
belongs_to :user
belongs_to :friend, :class_n...
“Keep Me Logged In” - the best approach
...age to page within the app. In this specific application, I'm storing the user_id , first_name and last_name of the person.
...
What is the advantage to using bloom filters?
...is that you can have only one filter (you check whether the combination of user_id + article_id is there)
bitcoin uses bloom filter for wallet synchronization
Akamai's web servers use Bloom filters to prevent "one-hit-wonders" from being stored in its disk caches. One-hit-wonders are web objects req...
Understanding REST: Verbs, error codes, and authentication
...e resource is "the user". You would need a PUT to http://example.com/users/USER_ID with the old and new passwords in the body. You are acting on "the user" resource, and a change password is simply an update request. It's quite similar to the UPDATE statement in a relational database.
My instinc...
How can I plot with 2 different y-axes?
....8 2015
75.2 2.0 74.6 2.3 74.2 1.7 2020
76.0 2.0 75.4 2.2 75.2 1.6 2025
76.8 1.9 76.2 2.1 76.1 1.6 2030
77.6 1.9 76.9 2.1 77.1 1.6 2035
78.4 1.9 77.6 2.0 77.9 1.7 2040
79.1 1.8 78.3 1.9 78.7 1.7 2045
79.8 1.8 79.0 1.9 79.5 1.7 2050
80.5 1.8 79.7 1.9 80.3 1.7 2055
81....
MVC (Laravel) where to add logic
...
// post as created by the current user.
$post->user_id = auth()->id();
}
$post->title = $this->title;
$post->description = $this->description;
// Perform other tasks, maybe fire an event, dispatch a job.
if ($post-...
Colors in JavaScript console
...sl(2014.2, 100%, 50%), -43px 374px hsl(2019.6, 100%, 50%), -42px 375px hsl(2025, 100%, 50%), -41px 376px hsl(2030.4, 100%, 50%), -39px 377px hsl(2035.8, 100%, 50%), -38px 378px hsl(2041.2, 100%, 50%), -36px 379px hsl(2046.6, 100%, 50%), -35px 380px hsl(2052, 100%, 50%), -33px 381px hsl(2057.4, 100%,...