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How do I create an average from a Ruby array?
...viously, an average only makes sense for things that can be averaged). But if you want to go that route, use this:
class Array
def sum
inject(0.0) { |result, el| result + el }
end
def mean
sum / size
end
end
If you haven't seen inject before, it's not as magical as it might appe...
Writing to an Excel spreadsheet
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You might want to mention that if you are running Python on Windows and have Excel installed on the same machine, you can use the Python COM interface to directly control Excel.
– Michael Dillon
Nov 18 '12 at 6:04
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How to force garbage collection in Java?
Is it possible to force garbage collection in Java, even if it is tricky to do? I know about System.gc(); and Runtime.gc(); but they only suggest to do GC. How can I force GC?
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HTTP POST Returns Error: 417 “Expectation Failed.”
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You can also specify that property in your app.config: <system.net> <settings> <servicePointManager expect100Continue="false"/>. nahidulkibria.blogspot.com/2009/06/…
– Andre Luus
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Initialize class fields in constructor or at declaration?
...declaration (null, false, 0, 0.0…).
Prefer initialization in declaration if you don't have a constructor parameter that changes the value of the field.
If the value of the field changes because of a constructor parameter put the initialization in the constructors.
Be consistent in your practice (t...
How do I use the lines of a file as arguments of a command?
Say, I have a file foo.txt specifying N arguments
10 Answers
10
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Annotating text on individual facet in ggplot2
...p + geom_text(data = ann_text,label = "Text")
It should work without specifying the factor variable completely, but will probably throw some warnings:
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SQL Query Where Field DOES NOT Contain $x
...OM y);
-- predefined list
SELECT a FROM x WHERE x.b NOT IN (1, 2, 3, 6);
If you are searching a string, go for the LIKE operator (but this will be slow):
-- Finds all rows where a does not contain "text"
SELECT * FROM x WHERE x.a NOT LIKE '%text%';
If you restrict it so that the string you are ...
String concatenation does not work in SQLite
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field1 || field2 returns null if one of the fields is null. One might want to do ifnull(field1,'')||ifnull(field2,''). That will give you a response if one or both fields are null. Then you get to figure out what you want to do if both were null.
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ResourceDictionary in a separate assembly
...cations. I could add them to the applications' assemblies, but it's better if I compile these resources in one single assembly and have my applications reference it, right?
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