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The special symbol .SD is available in j of DT[i,j,by], capturing the Subset of Data for each by group surviving the filter, i. .SDcols is a helper. Type ?`special-symbols` for the official docs. A reminder: DT[where, select|update|do, by] syntax is used to work with columns of a data.table. T...

The sqlite3 command-line shell implements an additional set of commands (which are not available in programs that use the SQLite library). Official documentation: Special commands to sqlite3

public static GameObject Find(string name); public static GameObject FindGameObjectWithTag(string tag); public static GameObject[] FindGameObjectsWithTag(string tag); public static Object FindObjectOfType(Type type); public static Object[] FindObjectsOfType(Type type); Which method to...

$ shopt -u option # Deactivate Bash's built-in 'option' $ shopt -s option # Activate Bash's built-in 'option' Character Classes Valid character classes for the [] glob are defined by the POSIX standard: alnum alpha ascii blank cntrl digit graph lower print punct space upper word xdig...

To run any of these examples just call them like that: static void Main() { new Program().ProcessDataAsync(); Console.ReadLine(); }

Hadoop v1 commands: hadoop fs -<command> Hadoop v2 commands: hdfs dfs -<command>

The Elvis operator evaluates based on Groovy-Truth of the condition-part.

newInstance : To create single instance of Facebook helper class. loginUser : To login user. signOut : To log out user. getCallbackManager : To get callback for Facebook. getLoginCallback : To get callback for Login. getKeyHash : To generate Facebook Key Hash. ParameterDetailsTAGA Strin...

ParameterDetailsvalueThe value produced by the binding source.valuesThe values array, produced by the binding source.targetTypeThe type of the binding target property.parameterThe converter parameter to use.cultureThe culture to use in the converter. What IValueConverter and IMultiValueConvertert...

Rust doesn't have a proper and idiomatic and safe way to lydiate with OS signals but there are some crates that provide signal handling but they are highly experimental and unsafe so be careful when using them. However there is a discussion in the rust-lang/rfcs repository about implementing nati...

Search qualid. (* for Coq 8.4 and newer versions *) SearchAbout qualid. (* deprecated synonym. *) ParameterDescriptionqualidThe identifier or pattern to search for. It can involve notations Before Coq 8.4, Search had the meaning of the current SearchHead: only search for facts where the p...