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How do I make a list of data frames?
...to your question, but you want to use = and not <- within the function call. If you use <-, you'll end up creating variables y1 and y2 in whatever environment you're working in:
d1 <- data.frame(y1 <- c(1, 2, 3), y2 <- c(4, 5, 6))
y1
# [1] 1 2 3
y2
# [1] 4 5 6
This won't have the s...
Just what is Java EE really? [closed]
...the libraries function outside of the application server environment?
Actually they can. Most of the libraries can be directly used standalone (in Java SE) or included in a .war (practically that's nearly always Tomcat). Some parts of Java EE, like JPA, have explicit sections in their respective sp...
What is the difference between ~> and >= when specifying rubygem in Gemfile?
... and use that until it reaches a maximum version. So ~>0.8.5 is semantically equivalent to:
gem "cucumber", ">=0.8.5", "<0.9.0"
The easy way to think about it is that you're okay with the last digit incrementing to some arbitrary value, but the ones preceding it in the string cannot be gr...
What do people think of the fossil DVCS? [closed]
... well and comparing makes it easier for me to get the idea across.
I'm totally in love with this SCM, so it's mostly points on the pluss side.
What I like about Fossil:
1) We have a bunch of machines (win/mac/a number of linux distros), and the single-executable installation is just as beautiful ...
What is the http-header “X-XSS-Protection”?
... Details are hard to find because it is a proprietary technology. Essentially, IE monitors if any of the suspiciously-looking parameters that the browser sends to a website come back in the response decoded. For example, if a user clicks on attack-me.com/… (which is "><script>alert('XS...
jQuery deferreds and promises - .then() vs .done()
...n't see the difference between using .then() & .done() for successful callbacks. I know Eric Hynds mentions that .done() and .success() map to the same functionality but I'm guessing so does .then() as all the callbacks are all invoked on a completion of a successful operation.
...
How do I check for null values in JavaScript?
...xible with regards to checking for "null" values. I'm guessing you're actually looking for empty strings, in which case this simpler code will work:
if(!pass || !cpass || !email || !cemail || !user){
Which will check for empty strings (""), null, undefined, false and the numbers 0 and NaN
Pleas...
Virtual functions and performance - C++
...e a very slight effect on performance, but it's unlikely to affect the overall performance of your application. Better places to look for performance improvements are in algorithms and I/O.
An excellent article that talks about virtual functions (and more) is Member Function Pointers and the Fastes...
Deep cloning objects
...ts too complex.
And with the use of extension methods (also from the originally referenced source):
In case of you prefer to use the new extension methods of C# 3.0, change the method to have the following signature:
public static T Clone<T>(this T source)
{
//...
}
Now the method call sim...
The Role Manager feature has not been enabled
...tried putting it in Application_Start and it says This method can only be called during the application's pre-start initialization phase.
– Maslow
May 8 '13 at 15:17
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