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A data.table is an enhanced version of the data.frame class from base R. As such, its class() attribute is the vector "data.table" "data.frame" and functions that work on a data.frame will also work with a data.table. There are many ways to create, load or coerce to a data.tabl...

A reminder: DT[where, select|update|do, by] syntax is used to work with columns of a data.table. The "where" part is the i argument The "select|update|do" part is the j argument These two arguments are usually passed by position instead of by name.

A reminder: DT[where, select|update|do, by] syntax is used to work with columns of a data.table. The "where" part is the i argument The "select|update|do" part is the j argument These two arguments are usually passed by position instead of by name.

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

Folding causes multiple lines of text to be collapsed and displayed as a single line. It is useful for hiding portions of a document considered unimportant for the current task. Folding is purely a visual change to the document: the folded lines are still present, unchanged. A fold is persistent....

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...

Entity Framework (EF) Core is a lightweight and extensible version of the popular Entity Framework data access technology. EF Core is an object-relational mapper (O/RM) that enables .NET developers to work with a database using .NET objects. It eliminates the need for most of the data-access code...

VHDL is a compound acronym for VHSIC (Very High Speed Integrated Circuit) HDL (Hardware Description Language). As a Hardware Description Language, it is primarily used to describe or model circuits. VHDL is an ideal language for describing circuits since it offers language constructs that easily d...

The INSERT INTO statement is used to insert new records in a table.

The ^M character stands for a carriage return in Vim (<c-m> or just <CR>). Vim displays this character when at least on line in the file uses LF line endings. In other words, when Vim consider a file to have fileformat=unix but some lines do have carriage returns (CR), the carriage r...