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On - window.location.hash - Change?
...by setting an interval that keeps checking the current hash, and comparing it against what it was before, we do this and let subscribers subscribe to a changed event that we fire if the hash changes.. its not perfect but browsers really don't support this event natively.
Update to keep this answe...
Calculate business days
...tion from the user comments on the date() function page in the PHP manual. It's an improvement of an earlier function in the comments that adds support for leap years.
Enter the starting and ending dates, along with an array of any holidays that might be in between, and it returns the working days ...
Factors in R: more than an annoyance?
... (and most users miss this subtlety). I say they are useful because model fitting packages like lme4 use factors and ordered factors to differentially fit models and determine the type of contrasts to use. And graphing packages also use them to group by. ggplot and most model fitting functions coerc...
How do I get the number of elements in a list?
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The len() function can be used with several different types in Python - both built-in types and library types. For example:
>>> len([1,2,3])
3
Official 2.x documentation is here: len()
Official 3.x documentation is here: len()
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Purge or recreate a Ruby on Rails database
...to do this:
This will reset your database and reload your current schema with all:
rake db:reset db:migrate
This will destroy your db and then create it and then migrate your current schema:
rake db:drop db:create db:migrate
All data will be lost in both scenarios.
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Postgres and Indexes on Foreign Keys and Primary Keys
... referencing side of foreign key relationships.
When Pg creates an implicit index it will emit a NOTICE-level message that you can see in psql and/or the system logs, so you can see when it happens. Automatically created indexes are visible in \d output for a table, too.
The documentation on uniq...
Copying files from one directory to another in Java
... directory to another (subdirectory) using Java. I have a directory, dir, with text files. I iterate over the first 20 files in dir, and want to copy them to another directory in the dir directory, which I have created right before the iteration.
In the code, I want to copy the review (which repre...
What is the difference between ELF files and bin files?
...rmat ELf file ,what is the difference between the two , especially the utility of ELF file.
4 Answers
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Circle-Rectangle collision detection (intersection)
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There are only two cases when the circle intersects with the rectangle:
Either the circle's centre lies inside the rectangle, or
One of the edges of the rectangle has a point in the circle.
Note that this does not require the rectangle to be axis-parallel.
(One way to s...
What's the difference between ConcurrentHashMap and Collections.synchronizedMap(Map)?
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For your needs, use ConcurrentHashMap. It allows concurrent modification of the Map from several threads without the need to block them. Collections.synchronizedMap(map) creates a blocking Map which will degrade performance, albeit ensure consistency (if used prop...