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Getting an object from an NSSet
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@fumoboy007: Consider how a hash table works: The container has an array of some number of buckets, and uses each incoming object's hash to determine which bucket that object should be in. For lookups such as member:, the container will only look in that one...
Selecting only numeric columns from a data frame
...e code to other answers:
x[, sapply(x, class) == "numeric"]
with a data.table
x[, lapply(x, is.numeric) == TRUE, with = FALSE]
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Extracting bits with a single multiplication
...K bits of a 64-bit integer. These lower K bits can then be used to index a table of pre-computed bitboards that representst the allowed squares that the piece on its origin square can actually move to (taking care of blocking pieces etc.)
A typical chess engine using this approach has 2 tables (on...
Remove header and footer from window.print()
...nt, if the page have a long element that scrolls past one page (like a big table), the margin is ignored and the printed version will look weird.
At the time original of this answer (May 2013), it only worked on Chrome, not sure about it now, never needed to try again. If you need support for a bro...
Convert a character digit to the corresponding integer in C
...wish to check isdigit(c) is true first. Note that you cannot completely portably do the same for letters, for example:
char c = 'b';
int x = c - 'a'; // x is now not necessarily 1
The standard guarantees that the char values for the digits '0' to '9' are contiguous, but makes no guarantees for ot...
A simple explanation of Naive Bayes Classification
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I realize that this is an old question, with an established answer. The reason I'm posting is that is the accepted answer has many elements of k-NN (k-nearest neighbors), a different algorithm.
Both k-NN and NaiveBayes are classification algorithms. Conceptually, k-NN uses...
How can I find the data structure that represents mine layout of Minesweeper in memory?
...o play. Feed it with binary and it shows you everything. Like accelerators table for me.
alt text http://files.getdropbox.com/u/1478671/2009-07-29_161532.jpg
You can see here, that F2 button corresponds to 510 in wParam.
Now let's get back to code, that handles WM_COMMAND. It compares wParam wit...
Eliminate space before \begin{itemize} [closed]
...ragraph still. This is still slightly annoying if you're putting them in a table without a preceding paragraph, as I am, but I suspect that there's a less ugly hack to fix this.
– Thomas Levine
Jan 30 '12 at 12:09
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Devise Secret Key was not set
...t done much) and did rails g devise user before I tried to create the user table and migrate. This fixed the problem.
– Matt
Feb 9 '14 at 23:10
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Delete all the queues from RabbitMQ?
...o showed *** Not found: /api/queues/%2F/name because the output is a ASCII table with a "name" column. I tweaked the command to be rabbitmqadmin list queues name | awk '!/--|name/ {print $2}' | xargs -I qn rabbitmqadmin delete queue name=qn to fix it.
– Mark Edington
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