Tutorial by Topics: rs

Some languages require you to define ahead of time what kind of variable you're declaring. JavaScript doesn't do that; it will try to figure that out on its own. Sometimes this can create unexpected behavior. If we use the following HTML <span id="freezing-point">0</span> ...

color: #rgb color: #rrggbb color: rgb[a](<red>, <green>, <blue>[, <alpha>]) color: hsl[a](<hue>, <saturation%>, <lightness%>[, <alpha>]) color: colorkeyword /* green, blue, yellow, orange, red, ..etc */

Pipe operators, available in magrittr, dplyr, and other R packages, process a data-object using a sequence of operations by passing the result of one step as input for the next step using infix-operators rather than the more typical R method of nested function calls. Note that the intended aim of p...

svn copy [BRANCH-FROM-URL] [BRANCH-TO-URL] -m <COMMIT-LOG-MESSAGE> svn copy [^/PATH-TO-BRANCH-FROM] [^/PATH-TO-BRANCH-TO] -m <COMMIT-LOG-MESSAGE> As you might have noticed, we use svn copy command to create branches, tags and shelves (we'll skip mentioning tags and shel...

ASDF - Another System Definition Facility ASDF is a tool for specifying how systems of Common Lisp software are made up of components (sub-systems and files), and how to operate on these components in the right order so that they can be compiled, loaded, tested, etc.

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

While not required, constructors in Java are methods recognized by the compiler to instantiate specific values for the class which may be essential to the role of the object. This topic demonstrates proper usage of Java class constructors. The Java Language Specification talks at length about ...

docker rm [OPTIONS] CONTAINER [CONTAINER...] docker attach [OPTIONS] CONTAINER docker exec [OPTIONS] CONTAINER COMMAND [ARG...] docker ps [OPTIONS] docker logs [OPTIONS] CONTAINER docker inspect [OPTIONS] CONTAINER|IMAGE [CONTAINER|IMAGE...] In the examples above, whenever container ...

Scollector supports tcollector style external collectors that can be used to send metrics to Bosun via custom scripts or executables. External collectors are a great way to get started collecting data, but when possible it is recommended for applications to send data directly to Bosun or to update...

Bitwise operations alter binary strings at the bit level. These operations are incredibly basic and are directly supported by the processor. These few operations are necessary in working with device drivers, low-level graphics, cryptography, and network communications. This section provides useful k...

SomeClass sc = new SomeClass { Property1 = value1, Property2 = value2, ... }; SomeClass sc = new SomeClass(param1, param2, ...) { Property1 = value1, Property2 = value2, ... } The constructor parentheses can only be omitted if the type being instantiated has a default (parameterless) const...

Recursion is mostly available in Perl-compatible flavors, such as: Perl PCRE Oniguruma Boost

shift shifts the positional parameters to the left so that $2 becomes $1, $3 becomes $2 and so forth. "$@" is an array of all the positional parameters passed to the script/function. "$*" is an string composed of all the positional parameters passed to the script/function. ...

A swarm is a number of Docker Engines (or nodes) that deploy services collectively. Swarm is used to distribute processing across many physical, virtual or cloud machines. Initialize a swarm: docker swarm init [OPTIONS] Join a swarm as a node and/or manager: docker swarm join [OPTIONS]...

The Traversable class generalises the function formerly known as mapM :: Monad m => (a -> m b) -> [a] -> m [b] to work with Applicative effects over structures other than lists.

Windows PowerShell is a shell and scripting component of the Windows Management Framework, an automation/configuration management framework from Microsoft built on the .NET Framework. PowerShell is installed by default on all supported versions of Windows client and server operating systems since ...

DECLARE cursor_name CURSOR [ LOCAL | GLOBAL ] [ FORWARD_ONLY | SCROLL ] [ STATIC | KEYSET | DYNAMIC | FAST_FORWARD ] [ READ_ONLY | SCROLL_LOCKS | OPTIMISTIC ] [ TYPE_WARNING ] FOR select_statement [ FOR UPDATE [ OF column_name [ ,...n ] ] ] Normally you would want to avoid using...

uname - to print information about your operating system. uname [OPTION]

Recursion occurs when a method calls itself. Such a method is called recursive. A recursive method may be more concise than an equivalent non-recursive approach. However, for deep recursion, sometimes an iterative solution can consume less of a thread's finite stack space. This topic includes examp...

While Python's context managers are widely used, few understand the purpose behind their use. These statements, commonly used with reading and writing files, assist the application in conserving system memory and improve resource management by ensuring specific resources are only in use for certain ...