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Replacement for “rename” in dplyr
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dplyr version 0.3 added a new rename() function that works just like plyr::rename().
df <-...
Changing the “tick frequency” on x or y axis in matplotlib?
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'Must Override a Superclass Method' Errors after importing a project into Eclipse
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Print list without brackets in a single row
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What is a plain English explanation of “Big O” notation?
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In a javascript array, how do I get the last 5 elements, excluding the first element?
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You can call:
arr.slice(Math.max(arr.length - 5, 1))
If you don't want to exclude the first element, use
arr.slice(Math.max(arr.length - 5, 0))
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How to succinctly write a formula with many variables from a data frame?
...in a formula to mean all the variables, it is the . identifier.
y <- c(1,4,6)
d <- data.frame(y = y, x1 = c(4,-1,3), x2 = c(3,9,8), x3 = c(4,-4,-2))
mod <- lm(y ~ ., data = d)
You can also do things like this, to use all variables but one (in this case x3 is excluded):
mod <- lm(y ~ ...
Underscore: sortBy() based on multiple attributes
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SQL MAX of multiple columns?
How do you return 1 value per row of the max of several columns:
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How to count the number of true elements in a NumPy bool array
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>>> import numpy as np
>>> boolarr = np.array([[0, 0, 1], [1, 0, 1], [1, 0, 1]], dtype=np.bool)
>>> boolarr
array([[False, False, True],
[ True, False, True],
[ True, False, True]], dtype=bool)
>>> np.sum(boolarr)
5
Of course, that is a bool...