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Remove duplicated rows using dplyr
...mple(0:1, 10, replace = T),
z = 1:10
)
One approach would be to group, and then only keep the first row:
df %>% group_by(x, y) %>% filter(row_number(z) == 1)
## Source: local data frame [3 x 3]
## Groups: x, y
##
## x y z
## 1 0 1 1
## 2 1 0 2
## 3 1 1 4
(In dplyr 0.2 you won't need...
RESTful Authentication
What does RESTful Authentication mean and how does it work? I can't find a good overview on Google. My only understanding is that you pass the session key (remeberal) in the URL, but this could be horribly wrong.
...
MySQL ON DUPLICATE KEY - last insert id?
...QL documentation example:
If a table contains an AUTO_INCREMENT column and INSERT ... UPDATE inserts a row, the LAST_INSERT_ID() function returns the AUTO_INCREMENT value. If the statement updates a row instead, LAST_INSERT_ID() is not meaningful. However, you can work around this by using LAST_...
How to split a delimited string in Ruby and convert it to an array?
...g to perform any action.
split() -> is an method, which split the input and store it as array.
'' or ' ' or ',' -> is an value, which is needed to be removed from given string.
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Running JAR file on Windows
...amed helloworld.jar .
In order to run it, I'm executing the following command in a command-line window:
25 Answers
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What is the correct way to make a custom .NET Exception serializable?
...lizable]
// Important: This attribute is NOT inherited from Exception, and MUST be specified
// otherwise serialization will fail with a SerializationException stating that
// "Type X in Assembly Y is not marked as serializable."
public class SerializableExceptionWithoutCustomProper...
How to calculate a logistic sigmoid function in Python?
...uld do it:
import math
def sigmoid(x):
return 1 / (1 + math.exp(-x))
And now you can test it by calling:
>>> sigmoid(0.458)
0.61253961344091512
Update: Note that the above was mainly intended as a straight one-to-one translation of the given expression into Python code. It is not t...
Extract substring in Bash
...he form someletters_12345_moreleters.ext , I want to extract the 5 digits and put them into a variable.
22 Answers
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How do I push a local repo to Bitbucket using SourceTree without creating a repo on bitbucket first?
Is there a way to import my local git repos to SourceTree and push them to my Bitbucket account, having new repos identical to my local repos be created on my account? Or do I have to make a repo online first and push to that? Github has a way to publish your local repos directly from it's client, a...
Convert NSArray to NSString in Objective-C
... @TechZen - no, because [array description] inserts newlines and the outer parentheses.
– Dave DeLong
Dec 1 '09 at 21:05
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