⎕pw ← 95

⍝ The square root of ¯1, a pure imaginary number.
⍙J ← 0J1

⍝ CMPLX is an array function.
∇ z ← m CMPLX n
  z ← m + ⍙J × n
∇

⍝ CMPLX0 is a scalar function.
∇ z ← CMPLX0 a; m; n
  ( m n ) ← a
  z ← m + ⍙J × n
∇

⍝ Euclidean division algorithm for Gaussian integers.
⍝ DIVJ is a scalar function.
∇ z ← a DIVJ b; q
  → ( b ≠ 0J0 ) / L0
  z ← 0 a
  → 0
 L0:
  z ← q , a - b × q ← CMPLX0 ⌊ ( 9 11 ) ○ a ÷ b
∇

⍝ Modulo function for Gaussian integers.  A test replacement for current
⍝ gnu-apl ∣ function applied to Gaussian integers.
⍝ MODJ is a scalar function.
∇ z ← a MODJ b
  z ← ↑ ¯1 ↑ b DIVJ a
∇

∇ z ← NORMJ m
  z ← m × + m
∇

∇ z ← SUE v
  z ← ( ( v ⍳ v ) = ⍳ ⍴ v ) / v
∇

∇ PLOT; ia; ra; bg; dmn; crs; unq; crsr; crsi; n; i
  ia ← 32 1 ⍴ ( 15 ⍴ ' ' ) , '-' , 16 ⍴ ' '
  ra ← ( 45 ⍴ ' ' ) , ' | ' , 45 ⍴ ' '
  bg ← ia , ( 31 93 ⍴ ' ∘ ' ) ,[ 1 ] ra
  bgn ← ¯16
  rng ← 31
  dmn ← bgn + ⍳ rng
  beta ← dmn ∘.+ 0J1 × dmn
  crs ← , ( ⎕ ← 2J6 ) ∣ beta
  unq ← ( crs ⍳ crs ) = ⍳ ⍴ crs
  ⎕ ← ⍴ ⎕ ← ucrs ← unq / crs
  crsr ← 9 ○ ucrs
  crsr ← 3 × 16 + crsr
  crsi ← 11 ○ ucrs
  crsi ← 16 + crsi
  n ← ⍴ crsr
  i ← 0
 L0:
  → ( i ≥ n ) / L1
  i ← i + 1
  bg[ crsi[ i ] ; crsr[ i ] ] ← '⎕'
  → L0
 L1:
  " "
  ⊖bg
∇

PLOT