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Assign multiple columns using := in data.table, by group
...hello
# 4: 1 4 hi hello
# 5: 2 5 hi hello
# 6: 3 6 hi hello
x[ , c("m>me m>an", "sum") := list(m>me m>an(b), sum(b)), by = a][]
# a b col1 col2 m>me m>an sum
# 1: 1 1 hi hello 2.5 5
# 2: 2 2 hi hello 3.5 7
# 3: 3 3 hi hello 4.5 9
# 4: 1 4 hi hello 2.5 5
# 5: 2 5 hi hello 3.5 7
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How would I get a cron job to run every 30 minutes?
...e a script every 30 minutes, on the hour and 30 minutes past the hour or som>me m>thing close. I have the following, but it doesn't seem to run on 0.
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Under what circumstances is an SqlConnection automatically enlisted in an ambient TransactionScope T
What does it m>me m>an for an SqlConnection to be "enlisted" in a transaction? Does it simply m>me m>an that commands I execute on the connection will participate in the transaction?
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Rails 3 check if attribute changed
...Check out ActiveModel::Dirty (available on all models by default). The docum>me m>ntation is really good, but it lets you do things such as:
@user.street1_changed? # => true/false
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Can I use `pip` instead of `easy_install` for `python setup.py install` dependency resolution?
...alls the package in editable mode. Any changes you make to the code will imm>me m>diately apply across the system. This is useful if you are the package developer and want to test changes. It also m>me m>ans you can't delete the folder without breaking the install.
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Why does Assert.AreEqual(T obj1, Tobj2) fail with identical byte arrays
I have two identical byte arrays in the following segm>me m>nt of code:
6 Answers
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How to load a UIView using a nib file created with Interface Builder
I'm trying to do som>me m>thing a bit elaborate, but som>me m>thing that should be possible. So here is a challenge for all you experts out there (this forum is a pack of a lot of you guys :) ).
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htaccess Access-Control-Allow-Origin
...the server after doing this? I apply the code above but it still won't let m>me m> access \.json, I changed js to json.
– shenkwen
Jun 21 '16 at 14:12
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What is the difference between Lisp-1 and Lisp-2?
...es to Clojure but I still do not understand properly. Can anyone enlighten m>me m>?
2 Answers
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Node.js Logging
Is there any library which will help m>me m> to handle logging in my Node.Js application? All I want to do is, I want to write all logs into a File and also I need an options like rolling out the file after certain size or date.
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