The Fine Print
The expressions require Dyalog APL
[136]
version 14.0 or later, with:
⎕io←0 | index origin |
⎕ml←1 | migration level |
⎕pp←6 | print precision |
⎕div←1 | the result of 0÷0 is 0 |
]box on | nested arrays displayed using boxes |
|
assert←{⍺←'assertion failure' ⋄ 0∊⍵:⍺ ⎕signal 8 ⋄ shy←0} |
| a utility
[124b] |
Some expressions use facilities not yet implemented as of this writing
(and may never be implemented in Dyalog APL).
They are:
x⍸y |
interval index
[52],
sorted x partitions the domain into contiguous intervals
and x⍸y is the index of the interval that contain y
|
⍸x |
where
[52],
{(,⍵)/,⍳⍴⍵} , indices of where boolean array x is 1
|
⊤x |
binary representation
[100],
2⊥⍣¯1⊢x
|
⊥x |
binary value
[100],
2⊥x
|
∞ | infinity
[123,
124a]
|
⍭ |
primes, ⍭i is the i-th prime, modeled by pco in the dfns workspace
[89]
|
⍢ | under
[51h], |
| f⍢g x ←→ g⍣¯1 f g x |
| x f⍢g y ←→ g⍣¯1 (g x)f(g y) |
|
⍫ |
obverse [51i],
f⍫g ←→ f except that f⍫g⍣¯1 ←→ g⍫f |
|