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How to force R to use a specified factor level as reference in a regression?
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See the relevel() function. Here is an example:
set.seed(123)
x <- rnorm(100)
DF <- data.frame(x = x,
y = 4 + (1.5*x) + rnorm(100, sd = 2),
b = gl(5, 20))
head(DF)
str(DF)
m1 <- lm(y ~ x + b, data = DF)
summary(m1)
Now alter the factor b ...
How does `is_base_of` work?
...ted to D* and B*. It's a user defined conversion sequence as described by 13.3.3.1.2 from Host<B, D> to D* and B* respectively. For finding conversion functions that can convert the class, the following candidate functions are synthesized for the first check function according to 13.3.1.5/1
D...
Send POST Request with Data Specified in File via Curl
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378
You're looking for the --data-binary argument:
curl -i -X POST host:port/post-file \
-H "Co...
Remove duplicated rows using dplyr
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139
Note: dplyr now contains the distinct function for this purpose.
Original answer below:
lib...
Rails nested form with has_many :through, how to edit attributes of join model?
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3 Answers
3
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How to merge dictionaries of dictionaries?
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return a
# works
print(merge({1:{"a":"A"},2:{"b":"B"}}, {2:{"c":"C"},3:{"d":"D"}}))
# has conflict
merge({1:{"a":"A"},2:{"b":"B"}}, {1:{"a":"A"},2:{"b":"C"}})
note that this mutates a - the contents of b are added to a (which is also returned). if you want to keep a you could call it like m...
Easy way to test a URL for 404 in PHP?
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edited Jan 3 '09 at 1:25
answered Jan 3 '09 at 0:56
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How to read environment variables in Scala
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237
Since Scala 2.9 you can use sys.env for the same effect:
scala> sys.env("HOME")
res0: Strin...
Reading a delimited string into an array in Bash
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339
In order to convert a string into an array, please use
arr=($line)
or
read -a arr <<...
What does static_assert do, and what would you use it for?
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83
Off the top of my head...
#include "SomeLibrary.h"
static_assert(SomeLibrary::Version > 2, ...