If it’s a list of string, just use the c() function : R> LL <- list(a=”tom”, b=”dick”) R> c(LL, c=”harry”) $a [1] “tom” $b [1] “dick” $c [1] “harry” R> class(LL) [1] “list” R> That works on vectors too, so do I get the bonus points? Edit (2015-Feb-01): This post is coming up on its … Read more
On Linux, see netem: the kernel already contains support for traffic shaping, and can simulate high latency, low bandwidth, packet losses, and all sort of other adverse conditions, even on a loopback device (so you don’t need a real, physical network to test across).
The second option really isn’t the same as the others – if the string is “///foo” it will become “foo” instead of “//foo”. The first option needs a bit more work to understand than the third – I would view the Substring option as the most common and readable. (Obviously each of them as an … Read more
Loops may achieve a performance gain for your program. Recursion may achieve a performance gain for your programmer. Choose which is more important in your situation!
System.currentTimeMillis() is obviously the most efficient since it does not even create an object, but new Date() is really just a thin wrapper about a long, so it is not far behind. Calendar, on the other hand, is relatively slow and very complex, since it has to deal with the considerably complexity and all the … Read more
Official web page ~50% faster Windows: Install “Intel x86 Emulator Accelerator (HAXM)” => SDK-Manager/Extras Install “Intel x86 Atom System Images” => SDK-Manager/Android 2.3.3 Go to the Android SDK root folder and navigate to extras\intel\Hardware_Accelerated_Execution_Manager. Execute file IntelHaxm.exe to install. (in Android Studio you can navigate to: Settings -> Android SDK -> SDK Tools -> Intel … Read more
The relational algebra allows interchangeability of the predicates in the WHERE clause and the INNER JOIN, so even INNER JOIN queries with WHERE clauses can have the predicates rearrranged by the optimizer so that they may already be excluded during the JOIN process. I recommend you write the queries in the most readable way possible. … Read more
What blocks Ruby, Python to get Javascript V8 speed? Nothing. Well, okay: money. (And time, people, resources, but if you have money, you can buy those.) V8 has a team of brilliant, highly-specialized, highly-experienced (and thus highly-paid) engineers working on it, that have decades of experience (I’m talking individually – collectively it’s more like centuries) in … Read more
The second (assuming you means CONTAINS, and actually put it in a valid query) should be faster, because it can use some form of index (in this case, a full text index). Of course, this form of query is only available if the column is in a full text index. If it isn’t, then only … Read more
Creating an exception object is not necessarily more expensive than creating other regular objects. The main cost is hidden in native fillInStackTrace method which walks through the call stack and collects all required information to build a stack trace: classes, method names, line numbers etc. Most of Throwable constructors implicitly call fillInStackTrace. This is where … Read more