suhr/nk.csv

## nk.csv

          
            Syntax
            Name
            Description
            Example
            Output

            
              +/x
              Sum
              Sum all value in x
              +/1 2 3 4 5
              15

            
              -':x
              Deltas
              Pairwise differences in x
              -':1 2 3 4
              1 1 1 1

            
              |+x
              Rotate matrix
              Rotate x counterclockwise
              |+3 3#!9
              (2 5 8;1 4 7;0 3 6)

            
              x@<x
              Sort
              Sort x
              {x@<x}@8 3 7 1
              1 3 7 8

            
              ?x,y
              Set union
              Unique elements from x and y
              ?"abac","adob"
              "abcdo"

            
              x^x^y
              Intersection
              Common elements from x and y
              {?x^x^y}["abac";"adob"]
              "aba"

            
              x|-x
              Absolute value
              Absolute value of x
              {x|-x}@-1
              1

            
              */y#x
              Power
              x in power of y (y>0)
              {*/y#x}[2;5]
              32

            
              y@(#y)!x+!#y
              Rotate left
              Rotate y by x elements to the left 
              {y@(#y)!x+!#y}[3;"abcde"]
              "deabc"

            
              `c$x-32*~"a{"'x
              Uppercase
              Upper case of all alphabetic chars
              {`c$x-32*~"a{"'x}@"happy"
              "HAPPY"

            
              @[x;i;:;v]
              Update
              Update value at x[i] with v
              a:+`a`b!(0 1 ; 2 3);@[a;0;:;(3,4)]
              +`a`b!(3 1;4 3)

            
              |/x
              Max, Any
              Largest element in x
              |/3 5 2
              5

            
              &/x
              Min, All
              Smallest element in x
              &/3 5 2
              2

            
              (+/x)%#x
              Average
              Arithmetic mean
              {(+/x)%#x}@1 2 3 4 5
              3.0

            
              z@y/(!y@<x)x
              Permute axes
              x⍉y⍴z
              {z@y/(!y@<x)x}[2 0 1; 2 3 4; `c$"A"+!24]
              "AMBNCODPEQFRGSHTIUJVKWLX"

            
              *|x
              Last
              Last element of x
              *|"abc"
              "c"

            
              *<x
              Index of min
              Index of smallest element in x
              *<"banana"
              1

            
              *>x
              Index of max
              Index of largest element in x
              *>"banana"
              2

            
              */x
              Product
              Multiply all values in x
              */2 3 4
              24

            
              *:/x
              Deep first
              First value in nested array x
              *:/(("ab";"cd");("ef";"gh"))
              "a"

            
              <<x
              Ascending ordinals
              Rank values in x by smallness
              <<"baka"
              2 0 3 1

            
              <>x
              Descending ordinals
              Rank values in x by greatness
              <>"baka"
              1 2 0 3

            
              ,/x
              Flatten
              Remove one level of nesting
              ,/(("ab";"cd");("ef";"gh"))
              ("ab";"cd";"ef";"gh")

            
              ,//x
              Enlist
              Flatten nested array into a list
              ,//(("ab";"cd");("ef";"gh"))
              "abcdefgh"

            
              x@&y
              Compress, Replicate
              Repeat each value in x y times
              "abcd"@&1 0 2 0
              "acc"

            
              x@\:y
              Apply list
              Apply each function in x to y
              (2+;3*)@\:!5
              (2 3 4 5 6;0 3 6 9 12)

            
              d:#'=x; @[(1+|/x)#0;!d;:;.d]
              Where Inverse
              Inverse to &
              {d:#'=x; @[(1+|/x)#0;!d;:;.d]}@ &0 2 1
              0 2 1

            
              (!1+#x)#\:x
              Prefixes
              Prefixes of x
              {(!1+#x)#\:x}"abcde"
              ("";,"a";"ab";"abc";"abcd";"abcde")

            
              (!1+#x)_\:x
              Suffixes
              Suffixes of x
              {(!1+#x)_\:x}"abcde"
              ("abcde";"bcde";"cde";"de";,"e";"")

            
              x,(-#x)_y
              Shift before
              Insert x into the start of y, shifting trailing elements out
              {x,(-#x)_y}["foo"; "abcde"]
              "fooab"

            
              ((#x)_y),x
              Shift after
              Insert x into the end of y, shifting leading elements out
              {((#x)_y),x}["foo"; "abcde"]
              "defoo"

            
              (&#'x)@<,/.x
              Group inverse
              Inverse to =
              {(&#'x)@<,/.x}@="banana"
              "banana"

            
              ~x'y
              In range
              For x~(a;b) is the same as (~a>y)&y<b
              ~2 5'!10
              0 0 1 1 1 0 0 0 0 0

            
              z=x|y&z
              In range (inclusive)
              Shorter version of (~x>z)&~z>y
              {z=x|y&z}[2;5;!10]
              0 0 1 1 1 1 0 0 0 0

            
              ~^y?x
              Elements of
              For each element in of x check if it's in y
              ~^"banana"?"bar"
              1 1 0

            
              x@.=x-!#x
              Consequents
              Consequent sequences of x
              {x@.=x-!#x}"abclmxyz"
              ("abc";"lm";"xyz")

            
              m:&x; y@m@.=m-!#m
              Cut by mask
              Cut y by mask x
              {m:&x; y@m@.=m-!#m}[0 1 1 0 1 1 1; "a42b123"]
              ("42";"123")
Syntax	Name	Description	Example	Output
+/x	Sum	Sum all value in x	+/1 2 3 4 5	15
-':x	Deltas	Pairwise differences in x	-':1 2 3 4	1 1 1 1
\|+x	Rotate matrix	Rotate x counterclockwise	\|+3 3#!9	(2 5 8;1 4 7;0 3 6)
x@<x	Sort	Sort x	{x@<x}@8 3 7 1	1 3 7 8
?x,y	Set union	Unique elements from x and y	?"abac","adob"	"abcdo"
x^x^y	Intersection	Common elements from x and y	{?x^x^y}["abac";"adob"]	"aba"
x\|-x	Absolute value	Absolute value of x	{x\|-x}@-1	1
*/y#x	Power	x in power of y (y>0)	{*/y#x}[2;5]	32
y@(#y)!x+!#y	Rotate left	Rotate y by x elements to the left	{y@(#y)!x+!#y}[3;"abcde"]	"deabc"
`c$x-32*~"a{"'x	Uppercase	Upper case of all alphabetic chars	{`c$x-32*~"a{"'x}@"happy"	"HAPPY"
@[x;i;:;v]	Update	Update value at x[i] with v	a:+`a`b!(0 1 ; 2 3);@[a;0;:;(3,4)]	+`a`b!(3 1;4 3)
\|/x	Max, Any	Largest element in x	\|/3 5 2	5
&/x	Min, All	Smallest element in x	&/3 5 2	2
(+/x)%#x	Average	Arithmetic mean	{(+/x)%#x}@1 2 3 4 5	3.0
z@y/(!y@<x)x	Permute axes	x⍉y⍴z	{z@y/(!y@<x)x}[2 0 1; 2 3 4; `c$"A"+!24]	"AMBNCODPEQFRGSHTIUJVKWLX"
*\|x	Last	Last element of x	*\|"abc"	"c"
*<x	Index of min	Index of smallest element in x	*<"banana"	1
*>x	Index of max	Index of largest element in x	*>"banana"	2
*/x	Product	Multiply all values in x	*/2 3 4	24
*:/x	Deep first	First value in nested array x	*:/(("ab";"cd");("ef";"gh"))	"a"
<<x	Ascending ordinals	Rank values in x by smallness	<<"baka"	2 0 3 1
<>x	Descending ordinals	Rank values in x by greatness	<>"baka"	1 2 0 3
,/x	Flatten	Remove one level of nesting	,/(("ab";"cd");("ef";"gh"))	("ab";"cd";"ef";"gh")
,//x	Enlist	Flatten nested array into a list	,//(("ab";"cd");("ef";"gh"))	"abcdefgh"
x@&y	Compress, Replicate	Repeat each value in x y times	"abcd"@&1 0 2 0	"acc"
x@\:y	Apply list	Apply each function in x to y	(2+;3*)@\:!5	(2 3 4 5 6;0 3 6 9 12)
d:#'=x; @[(1+\|/x)#0;!d;:;.d]	Where Inverse	Inverse to &	{d:#'=x; @[(1+\|/x)#0;!d;:;.d]}@ &0 2 1	0 2 1
(!1+#x)#\:x	Prefixes	Prefixes of x	{(!1+#x)#\:x}"abcde"	("";,"a";"ab";"abc";"abcd";"abcde")
(!1+#x)_\:x	Suffixes	Suffixes of x	{(!1+#x)_\:x}"abcde"	("abcde";"bcde";"cde";"de";,"e";"")
x,(-#x)_y	Shift before	Insert x into the start of y, shifting trailing elements out	{x,(-#x)_y}["foo"; "abcde"]	"fooab"
((#x)_y),x	Shift after	Insert x into the end of y, shifting leading elements out	{((#x)_y),x}["foo"; "abcde"]	"defoo"
(&#'x)@<,/.x	Group inverse	Inverse to =	{(&#'x)@<,/.x}@="banana"	"banana"
~x'y	In range	For x~(a;b) is the same as (~a>y)&y<b	~2 5'!10	0 0 1 1 1 0 0 0 0 0
z=x\|y&z	In range (inclusive)	Shorter version of (~x>z)&~z>y	{z=x\|y&z}[2;5;!10]	0 0 1 1 1 1 0 0 0 0
~^y?x	Elements of	For each element in of x check if it's in y	~^"banana"?"bar"	1 1 0
x@.=x-!#x	Consequents	Consequent sequences of x	{x@.=x-!#x}"abclmxyz"	("abc";"lm";"xyz")
m:&x; y@m@.=m-!#m	Cut by mask	Cut y by mask x	{m:&x; y@m@.=m-!#m}[0 1 1 0 1 1 1; "a42b123"]	("42";"123")