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When NOT to use yield (return) [duplicate]
... this O(n) times for a tree with n items, that makes the algorithm O(hn). And since the height of a binary tree is lg n <= h <= n, that means that the algorithm is at best O(n lg n) and at worst O(n^2) in time, and best case O(lg n) and worse case O(n) in stack space. It is O(h) in heap space...
Counting the number of elements with the values of x in a vector
... x creates a logical vector which is TRUE at every location that x occurs, and when suming, the logical vector is coerced to numeric which converts TRUE to 1 and FALSE to 0.
However, note that for floating point numbers it's better to use something like: sum(abs(numbers - x) < 1e-6).
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Positioning element at center of screen
...creen irrespective of screen size. In other words, the space left on 'top' and 'bottom' should be equal and space left on 'right' and 'left' sides should be equal. I would like to accomplish this with only CSS.
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How can I split a text into sentences?
...Russian -- see can NLTK/pyNLTK work “per language” (i.e. non-english), and how?.
– martineau
Jan 2 '11 at 0:28
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How do I create test and train samples from one dataframe with pandas?
I have a fairly large dataset in the form of a dataframe and I was wondering how I would be able to split the dataframe into two random samples (80% and 20%) for training and testing.
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php is null or empty?
...===.
When use ==, as you did, PHP treats NULL, false, 0, the empty string, and empty arrays as equal.
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How to find the statistical mode?
In R, mean() and median() are standard functions which do what you'd expect. mode() tells you the internal storage mode of the object, not the value that occurs the most in its argument. But is there is a standard library function that implements the statistical mode for a vector (or list)?
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write a shell script to ssh to a remote machine and execute commands
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There are multiple remote linux machines, and I need to write a shell script which will execute the same set of commands in each machine. (Including some sudo operations). How can this be done using shell scripting?
You can do this with ssh, for example:
#!/bin/ba...
Hidden features of Ruby
...actually wrote an gem at one point to do this, but my code was (a) a mess, and (b) slow. I'm very glad that the functionality has made it into core.
– James A. Rosen
Dec 14 '09 at 13:47
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PHP: How to generate a random, unique, alphanumeric string for use in a secret link?
How would it be possible to generate a random, unique string using numbers and letters for use in a verify link? Like when you create an account on a website, and it sends you an email with a link, and you have to click that link in order to verify your account
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