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Group by multiple columns in dplyr, using string vector input
...:
data = data.frame(
asihckhdoydkhxiydfgfTgdsx = sample(LETTERS[1:3], 100, replace=TRUE),
a30mvxigxkghc5cdsvxvyv0ja = sample(LETTERS[1:3], 100, replace=TRUE),
value = rnorm(100)
)
# get the columns we want to average within
columns = names(data)[-3]
library(dplyr)
df1 <- data %>...
Execute method on startup in Spring
...
answered Mar 8 '10 at 13:24
skaffmanskaffman
374k9292 gold badges779779 silver badges744744 bronze badges
...
Passport.js - Error: failed to serialize user into session
...owLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by \u003ca href=\"https://imgur.com/\"\u003e\u003csvg class=\"svg-icon\...
App Inventor 2 向心力实验App - 手机传感器探究向心力F与角速度ω、半径r...
...* ax + ay * ay)
// 计算向心力 F = m * a
var m = 文本输入框_质量.Text + 0
var r = 文本输入框_半径.Text + 0
global 向心力 = m * 向心加速度
标签_加速度.Text = join("加速度: ", 向心加速度, " m/s²")
标签_角速度.Text = join("角速度: ", 当...
What is mattr_accessor in a Rails module?
...
Orion EdwardsOrion Edwards
110k5858 gold badges215215 silver badges300300 bronze badges
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What is “entropy and information gain”?
...
1051
I assume entropy was mentioned in the context of building decision trees.
To illustrate, ima...
Convert a Git folder to a submodule retrospectively?
...ored files, a git clean -xd -f may be useful
– naught101
Mar 7 '13 at 0:17
...
Are PHP Variables passed by value or by reference?
... |
edited Jul 5 '16 at 10:56
Prabu Guna
31411 gold badge33 silver badges1313 bronze badges
answered A...
Structs in Javascript
...a retyping is still an issue, as there are more jumps than copying the new ___ ( , , , ) archetype. Also, there is no readability. Once you get used to coding, new READABLE_PART(ignore everything in here) becomes very scannable and self documenting, as opposed to {read: "ignore", everything: "igno...
Convert from MySQL datetime to another format with PHP
...PM), not "Y-m-d H:i:s".
– Rikki
Jan 10 '14 at 17:01
7
does not work for who? Accepted answer will...