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Why modelVersion of pom.xml is necessary and always set to 4.0.0?
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It is always set to 4.0.0 in Maven 2 and 3, because, at present, there is no other model.
Notice that modelVersion contains 4.0.0. That is currently the only supported POM version, and is always required. [source]
But it wouldn't necessarily need to always be ...
What is the most efficient string concatenation method in python?
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John FouhyJohn Fouhy
35.3k1818 gold badges5757 silver badges7373 bronze badges
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Linear Regression and group by in R
...e ~ year | state, data = d)
Coefficients:
(Intercept) year
CA -1.34420990 0.17139963
NY 0.00196176 -0.01852429
Degrees of freedom: 20 total; 16 residual
Residual standard error: 0.8201316
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How to pip install a package with min and max version range?
...hich should never be installed (theoretical api: pip install package<0.3 ).
3 Answers
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Pandas - How to flatten a hierarchical index in columns
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edited Jan 17 '14 at 19:36
answered Jan 24 '13 at 18:37
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Dynamically select data frame columns using $ and a character value
... a reproducible example below:
# set seed for reproducibility
set.seed(123)
df <- data.frame( col1 = sample(5,10,repl=T) , col2 = sample(5,10,repl=T) , col3 = sample(5,10,repl=T) )
# We want to sort by 'col3' then by 'col1'
sort_list <- c("col3","col1")
# Use 'do.call' to call order. Sec...
How to reorder data.table columns (without copying)
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Use setcolorder():
library(data.table)
x <- data.table(a = 1:3, b = 3:1, c = runif(3))
x
# a b c
# [1,] 1 3 0.2880365
# [2,] 2 2 0.7785115
# [3,] 3 1 0.3297416
setcolorder(x, c("c", "b", "a"))
x
# c b a
# [1,] 0.2880365 3 1
# [2,] 0.7785115 2 2
# [3,] 0.329741...
How to detect a Christmas Tree? [closed]
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+300
I have an approach which I think is interesting and a bit different from the rest. The main difference in my approach, compared to ...
NPM - How to fix “No readme data”
...o, when you read that warning, ensure that the problem is not related to a 3rd party package.
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