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How to avoid warning when introducing NAs by coercion
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142
Use suppressWarnings():
suppressWarnings(as.numeric(c("1", "2", "X")))
[1] 1 2 NA
This supp...
How to create an object for a Django model with a many to many field?
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248
You cannot create m2m relations from unsaved objects. If you have the pks, try this:
sample_o...
How to write multiple line string using Bash with variables?
...the command used (echo) is wrong.
Correct would be:
#!/bin/bash
kernel="2.6.39"
distro="xyz"
cat >/etc/myconfig.conf <<EOL
line 1, ${kernel}
line 2,
line 3, ${distro}
line 4 line
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EOL
cat /etc/myconfig.conf
This construction is referred to as a Here Document and can be found in t...
How to quit scala 2.11.0 REPL?
In the last version of scala (2.10.3) REPL, I can type exit to quit from REPL. However, in Scala 2.11.0 this doesn't work.
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Convert numpy array to tuple
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>>> arr = numpy.array(((2,2),(2,-2)))
>>> tuple(map(tuple, arr))
((2, 2), (2, -2))
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Enable 'xp_cmdshell' SQL Server
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answered Feb 27 '11 at 4:43
Pero P.Pero P.
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Regex to match a digit two or four times
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MySQL foreign key constraints, cascade delete
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392
If your cascading deletes nuke a product because it was a member of a category that was killed, ...
How to copy directories in OS X 10.7.3?
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2 Answers
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Adding a new array element to a JSON object
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242
JSON is just a notation; to make the change you want parse it so you can apply the changes to ...