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dplyr summarise: Equivalent of “.drop=FALSE” to keep groups with zero length in output
....drop argument that does just what you asked for:
df = data.frame(a=rep(1:3,4), b=rep(1:2,6))
df$b = factor(df$b, levels=1:3)
df %>%
group_by(b, .drop=FALSE) %>%
summarise(count_a=length(a))
#> # A tibble: 3 x 2
#> b count_a
#> <fct> <int>
#> 1 1 ...
Sort rows in data.table in decreasing order on string key `order(-x,v)` gives error on data.table 1.
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Android: TextView automatically truncate and replace last 3 char of String
...oid:inputType="text" . What I need now is something that replaces the last 3 characters of my String with " ... ". Since I'm not using a monospace font this will always be different depending on the letters used in my String . So I'm wondering what's the best way to get the last 3 characters of a...
How can I create a Set of Sets in Python?
... answered May 9 '11 at 0:18
a3nma3nm
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Turn off CSRF token in rails 3
...that I see here in stackoverflow but it seems they no longer work on rails 3.
3 Answers
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Build vs new in Rails 3
In the Rails 3 docs , the build method for associations is described as being the same as the new method, but with the automatic assignment of the foreign key. Straight from the docs:
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Static variables in member functions
...e of i will remain through out the program. To add an example:
A o1, o2, o3;
o1.foo(); // i = 1
o2.foo(); // i = 2
o3.foo(); // i = 3
o1.foo(); // i = 4
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in_array multiple values
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answered Sep 24 '11 at 23:51
Mark ElliotMark Elliot
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