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Opacity CSS not working in IE8

... No idea if this still applies to 8, but historically IE doesn't apply several styles to elements that don't "have layout." see: http://www.satzansatz.de/cssd/onhavinglayout.html share | ...
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Define all functions in one .R file, call them from another .R file. How, if possible?

How do I call functions defined in abc.R file in another file, say xyz.R? 1 Answer 1 ...
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How to find Unused Amazon EC2 Security groups

...AWS CLI tool, I found an easy way to get what I need: First, get a list of all security groups aws ec2 describe-security-groups --query 'SecurityGroups[*].GroupId' --output text | tr '\t' '\n' Then get all security groups tied to an instance, then piped to sort then uniq: aws ec2 describe-instance...
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Cannot ping AWS EC2 instance

... Thank you, I like this. I just want to allow the ping, not all. – Chu-Siang Lai Nov 25 '16 at 11:29 ...
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@property retain, assign, copy, nonatomic in Objective-C

...gners opted for the safer of the two solutions. In fact nonatomic is generally the better choice as it omits extremely expensive thread locks. The only reason to use atomic is if your property might be set from multiple threads (in which case omitting it can lead to an over-release or a leak). ...
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Building vs. Compiling (Java)

... The "Build" is a process that covers all the steps required to create a "deliverable" of your software. In the Java world, this typically includes: Generating sources (sometimes). Compiling sources. Compiling test sources. Executing tests (unit tests, integrat...
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What is the difference between persist() and merge() in JPA and Hibernate?

...these other entities are annotated with the cascade=PERSIST or cascade=ALL annotation element value or specified with the equivalent XML descriptor element. If X is a removed entity, it becomes managed. If X is a detached object, the EntityExistsException may be thrown when the...
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What is the difference between an interface and abstract class?

...'t do anything. It's just a pattern. For example (pseudo code): // I say all motor vehicles should look like this: interface MotorVehicle { void run(); int getFuel(); } // My team mate complies and writes vehicle looking that way class Car implements MotorVehicle { int fuel; vo...
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HTML/CSS: Making two floating divs the same height

... peculiar problem that I currently solve using a table , see below. Basically, I want to have two divs take up 100% of the available width, but only take up as much vertical space as needed (which isn't really that obvious from the picture). The two should at all times have the exact same height ...
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Convert data.frame column format from character to factor

...e to the world of R. mtcars #look at this built in data set str(mtcars) #allows you to see the classes of the variables (all numeric) #one approach it to index with the $ sign and the as.factor function mtcars$am <- as.factor(mtcars$am) #another approach mtcars[, 'cyl'] <- as.factor(mtcars[...