ag::k/kdb

{kxsystems}
Milano Milano's Page
Simon Simon's Page
why apl?
k: highest integer in float
k: matrix operations (xls sheet)
k: jdbc
k: ksql over sql92
k: re:fifo
k: fifo
k: cross correlation over the freq domain
k: Interpreted... _lsq example
k: rand num generator is good http://www.kx.com/listbox/kdb/msg00138.html

used Andale Mono, ping me if u think i should use another monospaced font.

/ still learning the language, i wish i had a more extensive knowledge of math and statistics 
/ to use k to its full power... for now only simple stuff to wrap my head around
/ stat examples @ http://www.kx.com/a/k/examples/stat.k


 

/ ALPHABET A  j: _ic "aA"
  j
97 65
  j+\:!9
(97 98 99 100 101 102 103 104 105
 65 66 67 68 69 70 71 72 73)
  _ci j+\:!30
("abcdefghijklmnopqrstuvwxyz{|}~"
 "ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^")

  3 + 125 * 6 % 100
10.5
  2 5 # !10
(0 1 2 3 4
 5 6 7 8 9)

  ???

/ SPELLING B  sentence:"index =. a.i.'aA'"
  "."=sentence
0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 0
  sentence
"index =. a.i.'aA'"
  s:&"."=sentence
  s
7 10 12
  (0,s) _ sentence
("index ="
 ". a"
 ".i"
 ".'aA'") 

/ GRAMMAR C  fahrenheit: 50
  (fahrenheit - 32) * 5 % 9
10.0
  prices: 3 1 4 2
  orders: 2 0 2 1
  orders * prices
6 0 8 2
  +/ orders * prices
16
  +\ 1 2 3 4 5
1 3 6 10 15
  2 3 * \ 1 2 3 4 5
1 2 3 4 5
  2 3 *\: 1 2 3 4 5
(2 4 6 8 10
 3 6 9 12 15)
  decr:{x-1}
  decr -1 0 1 2 3
-2 -1 0 1 2
         PARTS OF SPEECH
  50 fahrenheit  Nouns/Pronouns
  + - * % decr   Verbs/Proverbs
  / \            Adverbs
  &              Conjunction ???
  :              Verb-to-be
  ( )            Punctuation




/ TABLES Da  prices: 3 1 4 2
  orders: 2 0 2 1
  prices * orders
6 0 8 2
  prices *\: orders
(6 0 6 3
 2 0 2 1
 8 0 8 4
 4 0 4 2)

    TO READ A TABLE,
    BORDER IT BY ITS
    ARGUMENTS:

      * | 2 0 2 1
      -----------
      3 | 6 0 6 3
      1 | 2 0 2 1
      4 | 8 0 8 4
      2 | 4 0 4 2 

/ TABLES Db  n: 0 1 2 3
  n +/: n
(0 1 2 3
 1 2 3 4
 2 3 4 5
 3 4 5 6)

  n */: n
(0 0 0 0
 0 1 2 3
 0 2 4 6
 0 3 6 9)

  n ^/: n
(1 1 1 1.0
 0 1 2 3.0
 0 1 4 9.0
 0 1 8 27.0)

  ???

/ TABLES Dc  ???

  +

  +

  n: !4
  n =\: n
(1 0 0 0
 0 1 0 0
 0 0 1 0
 0 0 0 1)

  n <\: n
(0 1 1 1
 0 0 1 1
 0 0 0 1
 0 0 0 0)
  ~n >\: n
(1 1 1 1
 0 1 1 1
 0 0 1 1
 0 0 0 1)

/ TABLES Dd  text: " i sing of olaf "
  text: text,"glad and big"

  alph: " abcdefghijklmno"
  alph: alph,"pqrstuvwxyz"

  alph[!10]=\:text
(1 0 1 0 0 0 0 1 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 0
 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 1 0 0 0 0 0 0
 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0
 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0
 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0
 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1
 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0)

  2 13 #(#:'&:'alph=\:text)
(7 3 1 0 2 0 2 3 0 3 0 0 2
 0 2 2 0 0 0 1 0 0 0 0 0 0)
  2 13 # #:'&:'alph=\:text    / freq of alph in text
(7 3 1 0 2 0 2 3 0 3 0 0 2
 0 2 2 0 0 0 1 0 0 0 0 0 0)

  / 7 spaces alph[0]
  / 3 a    alph[1]
  / 1 b    alph[1]

/ CLASSIFICATION Ea  x: 1 2 3 4 5 6 7
  y: (x-3) * (x-5)
  y
8 3 0 -1 0 3 8

  range: |n+!(1+|/y-n:&/y)
  range
8 7 6 5 4 3 2 1 0 -1

  bc: range <\: y
  bc
(0 0 0 0 0 0 0
 1 0 0 0 0 0 1
 1 0 0 0 0 0 1
 1 0 0 0 0 0 1
 1 0 0 0 0 0 1
 1 0 0 0 0 0 1
 1 1 0 0 0 1 1
 1 1 0 0 0 1 1
 1 1 0 0 0 1 1
 1 1 1 0 1 1 1)

/ CLASSIFICATION Eb  x: 1 2 3 4 5 6 7
  y: (x-3) * (x-5)
  y
8 3 0 -1 0 3 8

  range: |n+!(1+|/y-n:&/y)
  range
8 7 6 5 4 3 2 1 0 -1




/

/

/ CLASSIFICATION +,* on subsets Ee  a: 0 0 0 0 1 1 1 1
  b: 0 0 1 1 0 0 1 1
  c: 0 1 0 1 0 1 0 1
  cct:(a;b;c)
  cct
(0 0 0 0 1 1 1 1
 0 0 1 1 0 0 1 1
 0 1 0 1 0 1 0 1)

  +/cct * 2 3 5
0 5 3 8 2 7 5 10
  +/+2 3 5 */:+cct
0 5 3 8 2 7 5 10

  */cct * 2 3 5
0 0 0 0 0 0 0 30






  g:"23456789"
  (!(-2)+#g) !\:g
("23456789"
"34567892"
"45678923"
"56789234"
"67892345"
"78923456")

  / last element
  / fast , slow
  v: 1000000 _draw 56
  #v
1000000

/ get last element
  \t do[100;v -1+#v] 
0
  \t do[100;*|v]
5618

  n&/:n
(0 0 0 0
 0 1 1 1
 0 1 2 2
 0 1 2 3)


/ alternate takes of 1s and 0s
  4#1 0
1 0 1 0
  1#1 0
,1
  5#1 0
1 0 1 0 1
  5#0 1
0 1 0 1 0

/ split string by spaces
  str:"this is a test."
  " "=str
0 0 0 0 1 0 0 1 0 1 0 0 0 0 0
  g:&" "=str
  g
4 7 9
  g:0,g
  g
0 4 7 9
  g _ str
("this"
 " is"
 " a"
 " test.")

  / reverse
  r:"reverse"
  s:`$r
  s
`reverse
  t:2#s 
  t
`reverse `reverse
  |:'$t
("esrever"
 "esrever")
  `$|:'$t
`esrever `esrever


  / ascii of number
  ,/$2 _vs 15
"1111"
  ,/$2 _vs 15345
"11101111110001"

  / freq of values
  l: 10000 _draw 5
  l[*:'p],'#:'p:=l
(4 1972
 0 1945
 3 2029
 1 2013
 2 2041)
  g[<g:l[*:'p],'#:'p:=l]
(0 1945
 1 2013
 2 2041
 3 2029
 4 1972)

/ wrong terminology(?)
/ flip matrix
  n:!4
  m:n|/:n
  m
(0 1 2 3
 1 1 2 3
 2 2 2 3
 3 3 3 3)
  ||:'m
(3 3 3 3
 3 2 2 2
 3 2 1 1
 3 2 1 0)
  |:'|m
(3 3 3 3
 3 2 2 2
 3 2 1 1
 3 2 1 0)


  / alpha
  _ci 97+!26
"abcdefghijklmnopqrstuvwxyz"

  2 # !3
0 1
  2 #/: !3
(0 0
 1 1
 2 2)
  2 #/ !3
2
  2 #\ !3
(2
 0 0
 ()
 2)
  2 #:\ !3
(0 1 2
 3
 1) 

  / matrix indexing
  g:(4 _draw -4)+/:!4
  g
(2 0 3 1
 3 1 4 2
 4 2 5 3
 5 3 6 4)
  g[0;]
2 0 3 1
  g[;1]
0 1 2 3
  g[;1 3]
(0 1
 1 2
 2 3
 3 4)
  g[1 3;]
(3 1 4 2
 5 3 6 4)


  / identity matrix
  n:!4
  n~'/:n
(1 0 0 0
 0 1 0 0
 0 0 1 0
 0 0 0 1)

  / searching vectors
  v:10000 _draw -10000
  \t do[10000;999 _in v]
630
/ using _bin is faster 
/ even for small vectors
  \t do[10000;v _bin 999]
10

 / string to symbol
  s:"applegate"
  `$($:'s)
`a `p `p `l `e `g `a `t `e
/ try take
  4 2#s
("ap"
 "pl"
 "eg"
 "at")
  `$(4 2#s)
`ap `pl `eg `at
  `$2 4#s
`appl `egat



  / _dot
  / x _dot y  ~  +/x*y

  / arthur says ~2001
  / +/x*y has 3 loads and 1 store per element
  / x _dot y has 2 loads

  / NB: for +/x*y , +/ is not sum
  g:2 2 _draw 5
  g
(1 4
 3 4)
  +g
(1 3
 4 4)

  / sum > 2gb
  s1
{+/0.0$$x}
  s1[50#*/(30#2)]
53687091200.0

 / MFTL 13C
/ k 
  s:"do you love me"
  |/s=/:"aeiou"
0 1 0 0 1 1 0 0 1 0 1 0 0 1
  s[&|/s=/:"aeiou"]
"oouoee"
  s[&~|/s=/:"aeiou"]
"d y lv m"
/ j
  or/'aeiou' =/ s
0 1 0 0 1 1 0 0 1 0 1 0 0 1



  / rotate until
/ last 2 numbers
  g:"23456789"
  (!(-2)+#g) !\:g 
("23456789"
"34567892"
"45678923"
"56789234"
"67892345"
"78923456") 
/ 4 take chars of each string
  4#'(!(-2)+#g)
("2345"
"3456"
"4567"
"5678"
"6789"
"7892")
/ form string to float
/ see last value in vector
  0.0$4#'(!(-2)+#g) !\:g   
2345 3456 4567 5678 6789 7892.0

/ experiment
  4#/:g
("2222"
 "3333"
 "4444"
 "5555"
 "6666"
 "7777"
 "8888"
 "9999")
  2 3 _ g
(,"3"
 "456789")

  / forward reduction
  (!#g) _\: g
("123456789"
 "23456789"
 "3456789"
 "456789"
 "56789"
 "6789"
 "789"
 "89"
 ,"9")



  /

  /

  /





/ Thu Aug 26 01:42:08 UTC 2004
/ what are you trying to do??
select from(update recno:$ from Quotes)where Bid=0
 
/ k cannot be used from ksql directly. wrap in function/proc i.e. find:{x?y}
/ select find[col,0] by Symbol from Quotes.

ksql>n rand 200
158 43 181 161 177 83 115 29 32 49
ksql>n rand -20
1 14 17 2 12 16 13 10 5 3
ksql>n rand -10
7 6 2 3 8 4 0 1 9 5
ksql>n rand -11
9 4 8 1 3 6 2 0 10 5
ksql>n rand -12
10 9 0 6 3 1 11 8 4 7

/----------------------------
/ Getting frequency of items
/----------------------------
  l:`a `a `b
  #:'=l
2 1
  =l
(0 1
 ,2)
  (*:'=l)
0 2

  (#:'=l),'(*:'=l)
(2 0
 1 2)
  l[*:'=l],'#:'=l
((`a;2)
 (`b;1))


  a:(!5;!10)
  a
(0 1 2 3 4
 0 1 2 3 4 5 6 7 8 9)
  fn/(!5;!10)
0 1 2 3 4,0 1 2 3 4 5 6 7 8 9
0 1 2 3 4 0 1 2 3 4 5 6 7 8 9
  g:fn/(!5;!10)
0 1 2 3 4,0 1 2 3 4 5 6 7 8 9
  g
0 1 2 3 4 0 1 2 3 4 5 6 7 8 9
  fn
{`0:(5:x),",",(5:y),"\n";:x,y}   /   :x,y    is the return part,    `0... is the print part


/ fn takes a list of count 2 (2 ~ #a)
/ g returns one thing, but prints another... pretty neat!



Last Updated:
$Wed Sep 28 18:13:40 UTC 2005$

/ ALPHABET A j: _ic "aA" j 97 65 j+\:!9 (97 98 99 100 101 102 103 104 105 65 66 67 68 69 70 71 72 73) _ci j+\:!30 ("abcdefghijklmnopqrstuvwxyz{\|}~" "ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^") 3 + 125 * 6 % 100 10.5 2 5 # !10 (0 1 2 3 4 5 6 7 8 9) ???	/ SPELLING B sentence:"index =. a.i.'aA'" "."=sentence 0 0 0 0 0 0 0 1 0 0 1 0 1 0 0 0 0 sentence "index =. a.i.'aA'" s:&"."=sentence s 7 10 12 (0,s) _ sentence ("index =" ". a" ".i" ".'aA'")	/ GRAMMAR C fahrenheit: 50 (fahrenheit - 32) * 5 % 9 10.0 prices: 3 1 4 2 orders: 2 0 2 1 orders * prices 6 0 8 2 +/ orders * prices 16 +\ 1 2 3 4 5 1 3 6 10 15 2 3 * \ 1 2 3 4 5 1 2 3 4 5 2 3 \: 1 2 3 4 5 (2 4 6 8 10 3 6 9 12 15) decr:{x-1} decr -1 0 1 2 3 -2 -1 0 1 2 PARTS OF SPEECH 50 fahrenheit Nouns/Pronouns + - % decr Verbs/Proverbs / \ Adverbs & Conjunction ??? : Verb-to-be ( ) Punctuation
/ TABLES Da prices: 3 1 4 2 orders: 2 0 2 1 prices * orders 6 0 8 2 prices \: orders (6 0 6 3 2 0 2 1 8 0 8 4 4 0 4 2) TO READ A TABLE, BORDER IT BY ITS ARGUMENTS: \| 2 0 2 1 ----------- 3 \| 6 0 6 3 1 \| 2 0 2 1 4 \| 8 0 8 4 2 \| 4 0 4 2	/ TABLES Db n: 0 1 2 3 n +/: n (0 1 2 3 1 2 3 4 2 3 4 5 3 4 5 6) n */: n (0 0 0 0 0 1 2 3 0 2 4 6 0 3 6 9) n ^/: n (1 1 1 1.0 0 1 2 3.0 0 1 4 9.0 0 1 8 27.0) ???	/ TABLES Dc ??? + + n: !4 n =\: n (1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1) n <\: n (0 1 1 1 0 0 1 1 0 0 0 1 0 0 0 0) ~n >\: n (1 1 1 1 0 1 1 1 0 0 1 1 0 0 0 1)
/ TABLES Dd text: " i sing of olaf " text: text,"glad and big" alph: " abcdefghijklmno" alph: alph,"pqrstuvwxyz" alph[!10]=\:text (1 0 1 0 0 0 0 1 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0) 2 13 #(#:'&:'alph=\:text) (7 3 1 0 2 0 2 3 0 3 0 0 2 0 2 2 0 0 0 1 0 0 0 0 0 0) 2 13 # #:'&:'alph=\:text / freq of alph in text (7 3 1 0 2 0 2 3 0 3 0 0 2 0 2 2 0 0 0 1 0 0 0 0 0 0) / 7 spaces alph[0] / 3 a alph[1] / 1 b alph[1]	/ CLASSIFICATION Ea x: 1 2 3 4 5 6 7 y: (x-3) * (x-5) y 8 3 0 -1 0 3 8 range: \|n+!(1+\|/y-n:&/y) range 8 7 6 5 4 3 2 1 0 -1 bc: range <\: y bc (0 0 0 0 0 0 0 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 0 0 0 0 0 1 1 1 0 0 0 1 1 1 1 0 0 0 1 1 1 1 0 0 0 1 1 1 1 1 0 1 1 1)	/ CLASSIFICATION Eb x: 1 2 3 4 5 6 7 y: (x-3) * (x-5) y 8 3 0 -1 0 3 8 range: \|n+!(1+\|/y-n:&/y) range 8 7 6 5 4 3 2 1 0 -1
/	/	*/ CLASSIFICATION +, on subsets Ee** a: 0 0 0 0 1 1 1 1 b: 0 0 1 1 0 0 1 1 c: 0 1 0 1 0 1 0 1 cct:(a;b;c) cct (0 0 0 0 1 1 1 1 0 0 1 1 0 0 1 1 0 1 0 1 0 1 0 1) +/cct * 2 3 5 0 5 3 8 2 7 5 10 +/+2 3 5 /:+cct 0 5 3 8 2 7 5 10 /cct * 2 3 5 0 0 0 0 0 0 0 30

g:"23456789" (!(-2)+#g) !\:g ("23456789" "34567892" "45678923" "56789234" "67892345" "78923456")	/ last element / fast , slow v: 1000000 _draw 56 #v 1000000 / get last element \t do[100;v -1+#v] 0 \t do[100;*\|v] 5618	n&/:n (0 0 0 0 0 1 1 1 0 1 2 2 0 1 2 3)
/ alternate takes of 1s and 0s 4#1 0 1 0 1 0 1#1 0 ,1 5#1 0 1 0 1 0 1 5#0 1 0 1 0 1 0	/ split string by spaces str:"this is a test." " "=str 0 0 0 0 1 0 0 1 0 1 0 0 0 0 0 g:&" "=str g 4 7 9 g:0,g g 0 4 7 9 g _ str ("this" " is" " a" " test.")	/ reverse r:"reverse" s:`$r s `reverse t:2#s t `reverse `reverse \|:'$t ("esrever" "esrever") `$\|:'$t `esrever `esrever
/ ascii of number ,/$2 _vs 15 "1111" ,/$2 _vs 15345 "11101111110001"	/ freq of values l: 10000 _draw 5 l[:'p],'#:'p:=l (4 1972 0 1945 3 2029 1 2013 2 2041) g[<g:l[:'p],'#:'p:=l] (0 1945 1 2013 2 2041 3 2029 4 1972)	/ wrong terminology(?) / flip matrix n:!4 m:n\|/:n m (0 1 2 3 1 1 2 3 2 2 2 3 3 3 3 3) \|\|:'m (3 3 3 3 3 2 2 2 3 2 1 1 3 2 1 0) \|:'\|m (3 3 3 3 3 2 2 2 3 2 1 1 3 2 1 0)
/ alpha _ci 97+!26 "abcdefghijklmnopqrstuvwxyz"	2 # !3 0 1 2 #/: !3 (0 0 1 1 2 2) 2 #/ !3 2 2 #\ !3 (2 0 0 () 2) 2 #:\ !3 (0 1 2 3 1)	/ matrix indexing g:(4 _draw -4)+/:!4 g (2 0 3 1 3 1 4 2 4 2 5 3 5 3 6 4) g[0;] 2 0 3 1 g[;1] 0 1 2 3 g[;1 3] (0 1 1 2 2 3 3 4) g[1 3;] (3 1 4 2 5 3 6 4)
/ identity matrix n:!4 n~'/:n (1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1)	/ searching vectors v:10000 _draw -10000 \t do[10000;999 _in v] 630 / using _bin is faster / even for small vectors \t do[10000;v _bin 999] 10	/ string to symbol s:"applegate" `$($:'s) `a `p `p `l `e `g `a `t `e / try take 4 2#s ("ap" "pl" "eg" "at") `$(4 2#s) `ap `pl `eg `at `$2 4#s `appl `egat
/ _dot / x _dot y ~ +/xy / arthur says ~2001 / +/xy has 3 loads and 1 store per element / x _dot y has 2 loads / NB: for +/x*y , +/ is not sum g:2 2 _draw 5 g (1 4 3 4) +g (1 3 4 4)	/ sum > 2gb s1 {+/0.0$$x} s1[50#*/(30#2)] 53687091200.0	/ MFTL 13C / k s:"do you love me" \|/s=/:"aeiou" 0 1 0 0 1 1 0 0 1 0 1 0 0 1 s[&\|/s=/:"aeiou"] "oouoee" s[&~\|/s=/:"aeiou"] "d y lv m" / j or/'aeiou' =/ s 0 1 0 0 1 1 0 0 1 0 1 0 0 1
/ rotate until / last 2 numbers g:"23456789" (!(-2)+#g) !\:g ("23456789" "34567892" "45678923" "56789234" "67892345" "78923456") / 4 take chars of each string 4#'(!(-2)+#g) ("2345" "3456" "4567" "5678" "6789" "7892") / form string to float / see last value in vector 0.0$4#'(!(-2)+#g) !\:g 2345 3456 4567 5678 6789 7892.0	/ experiment 4#/:g ("2222" "3333" "4444" "5555" "6666" "7777" "8888" "9999") 2 3 _ g (,"3" "456789")	/ forward reduction (!#g) _\: g ("123456789" "23456789" "3456789" "456789" "56789" "6789" "789" "89" ,"9")
/	/	/