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Specifying Maven's local repository location as a CLI parameter
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Petr KozelkaPetr Kozelka
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pandas resample documentation
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Matti JohnMatti John
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What is this: [Ljava.lang.Object;?
...out.println(new int[0][0][7]); // [[[I@xxxxx
System.out.println(new String[4][2]); // [[Ljava.lang.String;@xxxxx
System.out.println(new boolean[256]); // [Z@xxxxx
The reason why the toString() method on arrays returns String in this format is because arrays do not @Override the method inherited fr...
How to get a vertical geom_vline to an x-axis of class date?
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142
Try as.numeric(mydata$datefield[120]):
gg + geom_vline(xintercept=as.numeric(mydata$datefield[...
Array to Hash Ruby
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a = ["item 1", "item 2", "item 3", "item 4"]
h = Hash[*a] # => { "item 1" => "item 2", "item 3" => "item 4" }
That's it. The * is called the splat operator.
One caveat per @Mike Lewis (in the comments): "Be very careful with this. Ruby expands splats on ...
How do I convert a Ruby class name to a underscore-delimited symbol?
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Pandas aggregate count distinct
...about either of:
>>> df
date duration user_id
0 2013-04-01 30 0001
1 2013-04-01 15 0001
2 2013-04-01 20 0002
3 2013-04-02 15 0002
4 2013-04-02 30 0002
>>> df.groupby("date").agg({"duration": np.sum, "user_id": pd.Ser...
Plotting time in Python with Matplotlib
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