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Can dplyr package be used for conditional mutating?
...== 4, g := 3L]
df[a %in% c(2,5,7) | (a==1 & b==4), g := 2L]
Note the order of conditional statements is reversed to get g correctly. There's no copy of g made, even during the second assignment - it's replaced in-place.
On larger data this would have better performance than using nested if-el...
How do you detect where two line segments intersect? [closed]
...Specifically, h is how much you have to multiply the length of the line in order to exactly touch the other line.
Therefore, If h<0, it means the rectangle line is "behind" the given line (with "direction" being "from A to B"), and if h>1 the rectangle line is "in front" of the given line.
D...
Why doesn't the JVM cache JIT compiled code?
...ed goal is:
Save and reuse compiled native code from previous runs in order to
improve the startup time of large Java applications.
Hope this helps.
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Using StringWriter for XML Serialization
...f those answers are good on their own, they're not necessary in any way in order to answer your question. They deal with XML serialization in C# / .NET, but this question is really about saving XML in SQL Server. They provide info that is good to know, and might be better code than you originally pr...
How can I implement an Access Control List in my Web MVC application?
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How do I automatically scroll to the bottom of a multiline text box?
...kering scrollbar if you're calling it in a loop.
It also happens to be an order of magnitude faster than concatenating onto the .Text property. Though that might depend on how often you're calling it; I was testing with a tight loop.
This will not scroll if it is called before the textbox is sho...
Get the time difference between two datetimes
... [Math.floor(diff.asHours()), diff.minutes(), diff.seconds()].join(':') in order to get the desired result. without a decimal in the first part
– KyleM
Aug 2 '17 at 23:08
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Using ThreadPool.QueueUserWorkItem in ASP.NET in a high traffic scenario
... point:
Unless you are trying to parallelize a CPU-intensive operation in order to get it done faster on a low-load site, there is no point in using a worker thread at all.
That goes for both free threads, created by new Thread(...), and worker threads in the ThreadPool that respond to QueueUserWo...
Logging levels - Logback - rule-of-thumb to assign log levels
...significant happened; a new user came to the site, a page was rendered, an order was taken, a price was updated. This is the stuff excluded from info because there would be too much of it.
Trace is something i have never actually used.
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How to filter NSFetchedResultsController (CoreData) with UISearchDisplayController/UISearchBar
...ou just want to filter down the table and maintain all other aspects (sort order, cell layout, etc.) of the search results.
First, define two properties in your UITableViewController subclass (with the appropriate @synthesize and dealloc, if applicable):
@property (nonatomic, retain) UISearchDispl...