Expand description
Mirror of oxifft::dft::codelets::winograd_constants for use by codegen-impl.
Values must stay in sync — run the cross-validation test to verify.
All constants are f64 precision, computed from exact expressions
cos(2πk/N) and sin(2πk/N). The forward DFT convention used throughout
is W_N = e^{-2πi/N}, so:
- real parts: cos(2πk/N)
- imaginary parts (for the negative sign): -sin(2πk/N)
Constants§
- C3_1
- cos(2π/3) = −1/2
- C3_2
- sin(2π/3) = √3/2
- C5_COS1
- cos(2π/5)
- C5_COS2
- cos(4π/5)
- C5_SIN1
- sin(2π/5)
- C5_SIN2
- sin(4π/5)
- C7_COS1
- cos(2π/7)
- C7_COS2
- cos(4π/7)
- C7_COS3
- cos(6π/7)
- C7_SIN1
- sin(2π/7)
- C7_SIN2
- sin(4π/7)
- C7_SIN3
- sin(6π/7)
- C9_COS1
- cos(2π/9)
- C9_COS2
- cos(4π/9)
- C9_COS3
- cos(6π/9) = cos(2π/3) = -1/2
- C9_COS4
- cos(8π/9)
- C9_SIN1
- sin(2π/9)
- C9_SIN2
- sin(4π/9)
- C9_SIN3
- sin(6π/9) = sin(2π/3) = √3/2
- C9_SIN4
- sin(8π/9)
- C11_
COS1 - cos(2π/11)
- C11_
COS2 - cos(4π/11)
- C11_
COS3 - cos(6π/11)
- C11_
COS4 - cos(8π/11)
- C11_
COS5 - cos(10π/11)
- C11_
SIN1 - sin(2π/11)
- C11_
SIN2 - sin(4π/11)
- C11_
SIN3 - sin(6π/11)
- C11_
SIN4 - sin(8π/11)
- C11_
SIN5 - sin(10π/11)
- C13_
COS1 - cos(2π/13)
- C13_
COS2 - cos(4π/13)
- C13_
COS3 - cos(6π/13)
- C13_
COS4 - cos(8π/13)
- C13_
COS5 - cos(10π/13)
- C13_
COS6 - cos(12π/13)
- C13_
SIN1 - sin(2π/13)
- C13_
SIN2 - sin(4π/13)
- C13_
SIN3 - sin(6π/13)
- C13_
SIN4 - sin(8π/13)
- C13_
SIN5 - sin(10π/13)
- C13_
SIN6 - sin(12π/13)