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How to select the rows with maximum values in each group with dplyr? [duplicate]
I would like to select a row with maximum value in each group with dplyr.
6 Answers
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AtomicInteger lazySet vs. set
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atomics as well, so the method is supported across all of the
AtomicX classes.
For people who like to think of these operations in terms of
machine-level barriers on common multiprocessors, lazySet
provides a preceeding store-store barrier (which is either
a no-op or very cheap on ...
Identifying and removing null characters in UNIX
I have a text file containing unwanted null characters (ASCII NUL, \0 ). When I try to view it in vi I see ^@ symbols, interleaved in normal text. How can I:
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How do you round a number to two decimal places in C#?
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Here's some examples:
decimal a = 1.994444M;
Math.Round(a, 2); //returns 1.99
decimal b = 1.995555M;
Math.Round(b, 2); //returns 2.00
You might also want to look at bankers rounding / round-to-even with the following overload:
Math...
Xcode - How to fix 'NSUnknownKeyException', reason: … this class is not key value coding-compliant f
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How to check for Is not Null And Is not Empty string in SQL server?
...NULL or an empty string or a string consisting entirely of spaces are all excluded by this query.
SQL Fiddle
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How to write an async method with out parameter?
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You can't have async methods with ref or out parameters.
Lucian Wischik explains why this is not possible on this MSDN thread: http://social.msdn.microsoft.com/Forums/en-US/d2f48a52-e35a-4948-844d-828a1a6deb74/why-async-methods-cannot-have-ref-or-out-parameters
As for why async methods don't s...
Android TextView with Clickable Links: how to capture clicks?
I have a TextView which is rendering basic HTML, containing 2+ links. I need to capture clicks on the links and open the links -- in my own internal WebView (not in the default browser.)
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error: command 'gcc' failed with exit status 1 while installing eventlet
... need both python-dev and libevent-dev. Thanks!
– Alex Whittemore
May 17 '13 at 2:00
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For fedor...
What's the difference between CENTER_INSIDE and FIT_CENTER scale types?
...mpletely fits inside the container, and either the horizontal or vertical axis is going to be exact.
CENTER_INSIDE is going to center the image inside the container, rather than making the edges match exactly.
so if you had a square box that was 10" x 10" and an image that was 8"x8", the CENTER_I...