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Summarizing multiple columns with dplyr? [duplicate]
I'm struggling a bit with the dplyr-syntax. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
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What is the proper way to check for null values?
I love the null-coalescing operator because it makes it easy to assign a default value for nullable types.
10 Answers
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What's the meaning of interface{}?
I'm new to interfaces and trying to do SOAP request by github
6 Answers
6
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Why does MYSQL higher LIMIT offset slow the query down?
...or me it was from 2minutes to 1 second :)
Other interesting tricks here : http://www.iheavy.com/2013/06/19/3-ways-to-optimize-for-paging-in-mysql/
It works too with strings
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Understanding the difference between __getattr__ and __getattribute__
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Rich vs Anemic Domain Model [closed]
...ttern from an OO perspective.
For a deeper insight take a look at my blog https://www.link-intersystems.com/blog/2011/10/01/anemic-vs-rich-domain-models/
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The difference between the Runnable and Callable interfaces in Java
What is the difference between using the Runnable and Callable interfaces when designing a concurrent thread in Java, why would you choose one over the other?
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How can I create a Set of Sets in Python?
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Method call if not null in C#
Is it possible to somehow shorten this statement?
11 Answers
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What are the use(s) for tags in Go?
...ontrol how fields are interpreted during encoding and decoding:
Try live: http://play.golang.org/p/BMeR8p1cKf
package main
import (
"fmt"
"encoding/json"
)
type Person struct {
FirstName string `json:"first_name"`
LastName string `json:"last_name"`
MiddleName string `json:...