Function index

Here is a table of symbols we have used and how to type them in RIDE.

It might be useful to review this page as you are doing the read and write exercises in the next sections.

New functions

Traditional functions

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`∇`	Del	Tradfn	`PREFIX` `G`	`V` `V` `Tab`
`→`	Right arrow	Branch	`PREFIX` `]`	`-` `>` `Tab`
`≢`	Not match	Tally	`PREFIX` `"`	`7` `=` `Tab`

System variables and constants

Name	Meaning
`⎕A`	The upper-case English alphabet, `'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
`⎕CT`	Comparison tolerance, from `0` (exact comparison) up to `10*¯10`
`⎕PP`	Print precision, the number of digits displayed
`⎕IO`	Index origin, either `1` (the default) or `0`

System functions

Name	Meaning
`⎕NC`	Name classification, returns `0` when a variable name is unused
`⎕DMX`	Diagnostic message object; `⎕DMX.Message` holds the reason for the last error
`⎕EN`	Error number of the last error
`⎕STOP`	Sets or lists the breakpoints of a function
`⎕TRACE`	Sets or lists the trace points of a function, which print the result of a line as it runs
`⎕NGET`	Reads a text file
`⎕NPUT`	Writes a text file
`⎕NEXISTS`	Returns `1` if a file exists
`⎕NINFO`	Properties of a file, such as its name, type and size
`⎕NDELETE`	Deletes a file
`⎕CSV`	Reads character separated values into a matrix, with a type per column
`⎕NTIE`	Ties a file, returning a tie number
`⎕NSIZE`	Size in bytes of a tied file
`⎕NREAD`	Reads from a tied file, advancing its position
`⎕NNUMS`	Tie numbers of all tied files
`⎕NUNTIE`	Unties a file
`⎕FCREATE`	Creates and ties a component file
`⎕FAPPEND`	Appends an array to a component file as a new component
`⎕FREAD`	Reads a component
`⎕FREPLACE`	Replaces a component
`⎕FSIZE`	Component numbers and size of a component file
`⎕FTIE`	Ties an existing component file
`⎕FUNTIE`	Unties a component file
`⎕VFI`	Verify and fix input: which words of a text are valid numbers, and their values
`⎕NS`	Creates a namespace
`⎕NL`	Name list: the names in a namespace, selected by name class

User commands

Name	Meaning
`]LINK.Create`	Links a folder of source files to a namespace
`]CD`	Shows or changes the current working directory
`]Activate`	Activates an experimental tool shipped with Dyalog, such as Tatin or Cider
`]UReset`	Rebuilds the cached list of user commands
`]TATIN.Version`	Version of Tatin
`]TATIN.ListRegistries`	Lists the package registries
`]TATIN.ListPackages`	Lists the packages of a registry
`]TATIN.LoadPackages`	Loads packages into a namespace
`]CIDER.Version`	Version of Cider
`]CIDER.CreateProject`	Turns a folder into a project
`]CIDER.OpenProject`	Opens a project, linking its source and loading its dependencies
`]CIDER.AddTatinDependencies`	Adds Tatin packages as dependencies of a project
`]CIDER.RunTests`	Runs the test suite of a project
`]CIDER.Make`	Builds a new version of a project

Control structures

Name	Meaning
`:If`	Conditional execution, with `:ElseIf`, `:Else` and `:EndIf`
`:Trap`	Error trapping by error number, with `:Case`, `:Else` and `:EndTrap`
`:For`	Iteration over the items of an array, with `:In` and `:EndFor`
`:Namespace`	A namespace written as a script, with `:EndNamespace`

Old functions

Symbol	Name	Function (Monadic/Dyadic)	Key combination (Prefix)	Key combination (Tab)
`+`	Plus	Conjugate / Plus	`+`	`+`
`-`	Minus	Negate / Minus	`-`	`-`
`×`	Times	Direction / Times	`PREFIX` `-`	`x` `x` `Tab`
`÷`	Divide	Divide	`PREFIX` `=`	`:` `-` `Tab`
`*`	Star	Power	`*`	`*`
`¯`	High minus	Negative	`PREFIX` `2`	`-` `-` `Tab`
`⍝`	Lamp	Comment	`PREFIX` `,`	`o` `n` `Tab`
`←`	Assignment symbol	Assign	`PREFIX` `[`	`<` `-` `Tab`
`⎕`	Quad	Output	`PREFIX` `L`	`[` `]` `Tab`
`⍴`	Rho	Shape / Reshape	`PREFIX` `R`	`r` `r` `Tab`
`,`	Comma	Ravel / Catenate	`,`	`,`
`{}`	Braces	Dfn	`{` `}`	`{` `}`
`⍺`	Alpha	Left argument	`PREFIX` `A`	`a` `a` `Tab`
`⍵`	Omega	Right argument	`PREFIX` `W`	`w` `w` `Tab`
`⋄`	Diamond	Statement separator	`PREFIX` `	`<` `>` `Tab`
`⍬`	Zilde	Empty numeric vector	`PREFIX` `}`	`0` `~` `Tab`
`⌈`	Upstile	Ceiling / Maximum	`PREFIX` `S`	`7` `7` `Tab`
`⌊`	Downstile	Floor / Minimum	`PREFIX` `D`	`l` `l` `Tab`
`\|`	Stile	Magnitude / Residue	`PREFIX` `M`	`\|`
`∨`	Logical OR	Greatest common divisor, Or	`PREFIX` `9`	`v` `v` `Tab`
`∧`	Logical AND	Lowest common multiple, And	`PREFIX` `0`	`^` `^` `Tab`
`○`	Circle	Pi times / Circular	`PREFIX` `O`	`O` `O` `Tab`
`!`	Exclamation mark	Factorial / Binomial	`PREFIX` `_`	`!`
`=`	Equal	Equal to	`PREFIX` `5`	`=`
`≠`	Not equal	Not equal to	`PREFIX` `8`	`=` `/` `Tab`
`<`	Less than	Less than	`PREFIX` `3`	`<`
`≤`	Less than or equal to	Less than or equal to	`PREFIX` `4`	`<` `=` `Tab`
`>`	Greater than	Greater than	`PREFIX` `7`	`>`
`≥`	Greater than or equal to	Greater than or equal to	`PREFIX` `6`	`>` `=` `Tab`
`≡`	Equal underbar	Depth / Match	`PREFIX` `:`	`=` `=` `Tab`
`~`	Tilde	Not / Without	`PREFIX` `T`	`~`
`⍲`	Up caret tilde	Nand	`PREFIX` `)`	`^` `~` `Tab`
`⍱`	Down caret tilde	Nor	`PREFIX` `(`	`v` `~` `Tab`
`∇`	Del	Recursion, Derived function	`PREFIX` `G`	`V` `V` `Tab`
`:`	Colon	Guard	`:`	`:`
`⊣`	Left tack	Same / Left	`PREFIX` `\|`	`-` `\|` `Tab`
`⊢`	Right tack	Same / Right	`PREFIX` `\`	`\|` `-` `Tab`
`⍤`	Jot diaeresis	Rank / Atop	`PREFIX` `Shift`+`J`	`o` `:` `Tab`
`∘`	Jot	Bind	`PREFIX` `J`	`o` `o` `Tab`
`⍨`	Tilde diaeresis	Swap, Self	`PREFIX` `Shift`+`T`	`~` `:` `Tab`
`⍳`	Iota	Index generator / Index of	`PREFIX` `I`	`i` `i` `Tab`
`?`	Question mark	Roll / Deal	`PREFIX` `Q`	`?`
`/`	Slash	Replicate, Compress, Reduce	`/`	`/`
`\`	Backslash	Scan	`\`	`\`
`⍋`	Grade up	Grade up	`PREFIX` `$`	`A` `\|` `Tab`
`⍒`	Grade down	Grade down	`PREFIX` `#`	`V` `\|` `Tab`
`↑`	Up arrow	Mix / Take	`PREFIX` `Y`	`^` `\|` `Tab`
`↓`	Down arrow	Split / Drop	`PREFIX` `U`	`v` `\|` `Tab`
`[]`	Brackets	Index, Bracket axis	`[` `]`	`[` `]`
`⊃`	Right shoe	Pick	`PREFIX` `X`	`)` `)` `Tab`
`∊`	Epsilon	Enlist / Member of	`PREFIX` `E`	`e` `e` `Tab`
`⍸`	Iota underbar	Where / Interval index	`PREFIX` `Shift`+`I`	`i` `_` `Tab`
`⍷`	Epsilon underbar	Find	`PREFIX` `Shift`+`E`	`e` `_` `Tab`
`⌸`	Quad equal	Key	`PREFIX` `Shift`+`K`	`[` `=` `Tab`
`∪`	Down shoe	Unique / Union	`PREFIX` `V`	`u` `u` `Tab`
`∩`	Up shoe	Intersection	`PREFIX` `C`	`n` `n` `Tab`
`⊂`	Left shoe	Enclose / Partitioned enclose	`PREFIX` `Z`	`(` `(` `Tab`
`¨`	Diaeresis	Each	`PREFIX` `1`	`:` `:` `Tab`
`⌿`	Slash bar	Reduce first	`PREFIX` `/`	`/` `-` `Tab`
`⌷`	Squad	Index	`PREFIX` `Shift`+`L`	`[` `\|` `Tab`
`⍪`	Comma bar	Table / Catenate first	`PREFIX` `<`	`,` `-` `Tab`
`⍉`	Circle backslash	Transpose / Reorder axes	`PREFIX` `^`	`O` `\` `Tab`
`⌽`	Circle stile	Reverse / Rotate	`PREFIX` `%`	`O` `\|` `Tab`
`⊖`	Circle bar	Reverse first / Rotate first	`PREFIX` `&`	`O` `-` `Tab`
`⊆`	Left shoe underbar	Partition	`PREFIX` `Shift`+`Z`	`(` `_` `Tab`
`⍎`	Hydrant	Execute	`PREFIX` `;`	`o` `_` `Tab`
`⍕`	Thorn	Format	`PREFIX` `'`	`o` `T` `Tab`
`∘.`	Jot dot	Outer product	`PREFIX` `J` then `.`	`o` `o` `Tab` then `.`
`.`	Dot	Inner product	`.`	`.`
`⌹`	Domino	Matrix inverse / Matrix divide	`PREFIX` `+`	`[` `-` `Tab`
`⊤`	Down tack	Encode	`PREFIX` `N`	`T` `T` `Tab`
`⊥`	Up tack	Decode	`PREFIX` `B`	`\|` `_` `Tab`
`⍣`	Star diaeresis	Power, Until	`PREFIX` `Shift`+`P`	`*` `:` `Tab`
`@`	At	At	`@`	`@`
`⍺⍺`	Alpha alpha	Left operand	`PREFIX` `A` (twice)	`a` `a` `Tab` (twice)
`⍵⍵`	Omega omega	Right operand	`PREFIX` `W` (twice)	`w` `w` `Tab` (twice)
`∇∇`	Double del	Recursion	`PREFIX` `G` (twice)	`V` `V` `Tab` (twice)