func TestFFT2(t *testing.T) {
for _, ft := range fft2Tests {
v := FFT2Real(ft.in)
if !dsputils.PrettyClose2(v, ft.out) {
t.Error("FFT2 error\ninput:", ft.in, "\noutput:", v, "\nexpected:", ft.out)
}
vi := IFFT2(ft.out)
if !dsputils.PrettyClose2(vi, dsputils.ToComplex2(ft.in)) {
t.Error("IFFT2 error\ninput:", ft.out, "\noutput:", vi, "\nexpected:", dsputils.ToComplex2(ft.in))
}
}
}
func makeKSpaceData() [][]complex64 {
nX, nY := 256, 128
square := make([][]float64, nY)
for y := 0; y < nY; y++ {
square[y] = make([]float64, nX)
for x := 0; x < nX; x++ {
if (x > nX/4) && (x < 3*nX/4) && (y > nY/8) && (y < 7*nY/8) {
square[y][x] = 1.0
} else {
square[y][x] = 0.0
}
}
}
saveFloat64Image(square, "square.png")
squarec := dsputils.ToComplex2(square)
shift := fftshift2(squarec)
saveCmplx128Image(shift, "shifted.png")
fft_square := fftshift2(fft.FFT2(fftshift2(squarec)))
data := make([][]complex64, nY)
for a := 0; a < nY; a++ {
data[a] = make([]complex64, nX)
for b := 0; b < nX; b++ {
data[a][b] = complex64(fft_square[a][b])
}
}
return data
}
// IFFT2Real returns the 2-dimensional, inverse FFT of the real-valued matrix.
func IFFT2Real(x [][]float64) [][]complex128 {
return IFFT2(dsputils.ToComplex2(x))
}
