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How accurately should I store latitude and longitude?
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Actually, equator is best case. One latitude and one longitude degree are the same size at the equator (69 miles), but one degree of longitude shrinks to zero as it approaches either of the poles. Here's a very nice explanation: nationalatlas.gov/articles/mapping/a_latl...
What data type to use for hashed password field and what length?
... @Hippo: Please, don't use the username as the salt. Generate a random salt per user.
– Bill Karwin
Sep 15 '10 at 18:38
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Purge or recreate a Ruby on Rails database
...ave a dev Ruby on Rails database full of data. I want to delete everything and rebuild the database. I'm thinking of using something like:
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Are loops really faster in reverse?
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is it worth to introduce a variable for array.length and use it in the for loop's head?
– ragatskynet
Oct 30 '12 at 10:13
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What is the difference between & and && in Java?
...& operator in Java is used for verifying whether both its boolean operands are true , and the & operator is used to do Bit-wise operations on two integer types.
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Regex: Specify “space or start of string” and “space or end of string”
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You can use any of the following:
\b #A word break and will work for both spaces and end of lines.
(^|\s) #the | means or. () is a capturing group.
/\b(stackoverflow)\b/
Also, if you don't want to include the space in your match, you can use lookbehind/aheads.
(?<=\...
How can I determine whether a 2D Point is within a Polygon?
..., but macOS for example uses float for everything. macOS only knows points and a point can translate to one pixel, but depending on monitor resolution, it might translate to something else. On retina screens half a point (0.5/0.5) is pixel. Still, I never noticed that macOS UIs are significantly slo...
Javascript Drag and drop for touch devices [closed]
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You can use the Jquery UI for drag and drop with an additional library that translates mouse events into touch which is what you need, the library I recommend is https://github.com/furf/jquery-ui-touch-punch, with this your drag and drop from Jquery UI should ...
Rails find_or_create_by more than one attribute?
There is a handy dynamic attribute in active-record called find_or_create_by:
5 Answers
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Change column type from string to float in Pandas
I want to convert a table, represented as a list of lists, into a Pandas DataFrame . As an extremely simplified example:
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