private static int R2rLength(int n, FftwR2rKind kind)
{
switch (kind)
{
case FftwR2rKind.FFTW_R2HC:
case FftwR2rKind.FFTW_HC2R:
case FftwR2rKind.FFTW_DHT:
return(n);
case FftwR2rKind.FFTW_REDFT00:
return(2 * (n - 1));
case FftwR2rKind.FFTW_REDFT10:
case FftwR2rKind.FFTW_REDFT01:
case FftwR2rKind.FFTW_REDFT11:
return(2 * n);
case FftwR2rKind.FFTW_RODFT00:
return(2 * (n + 1));
case FftwR2rKind.FFTW_RODFT10:
case FftwR2rKind.FFTW_RODFT01:
case FftwR2rKind.FFTW_RODFT11:
return(2 * n);
default:
throw new ArgumentException("Real to real transform kind must be one of allowed values in " +
"FftwR2rKind enum.", nameof(kind));
}
}
public static FftwPlan DftR2r3D(int n0, int n1, int n2, out FftwArray inArray, out FftwArray outArray,
FftwR2rKind kind0, FftwR2rKind kind1, FftwR2rKind kind2, FftwFlags flags = FftwFlags.FFTW_MEASURE)
{
int length = R2rLength(n0, n1, n2, kind0, kind1, kind2);
inArray = new FftwArray(length);
outArray = new FftwArray(length);
return(DftR2r3D(n0, n1, n2, inArray, outArray, kind0, kind1, kind2, flags));
}
public static FftwPlan DftR2r3D(int n0, int n1, int n2, FftwArray inArray, FftwArray outArray,
FftwR2rKind kind0, FftwR2rKind kind1, FftwR2rKind kind2, FftwFlags flags = FftwFlags.FFTW_MEASURE)
{
int length = R2rLength(n0, n1, n2, kind0, kind1, kind2);
ValidateArray(inArray, length, nameof(inArray));
ValidateArray(outArray, length, nameof(outArray));
return(new FftwPlan(flags,
fftw_plan_r2r_3d(n0, n1, n2,
inArray.Pointer, outArray.Pointer,
kind0, kind1, kind2, (uint_t)flags),
inArray, outArray));
}
public static extern fftw_plan fftw_plan_r2r_3d(
int_t n0, int_t n1, int_t n2,
double_ptr in_ptr, double_ptr out_ptr,
FftwR2rKind kind0, FftwR2rKind kind1, FftwR2rKind kind2,
uint_t flags);
public static extern fftw_plan fftw_plan_r2r_1d(
int_t n0,
double_ptr in_ptr, double_ptr out_ptr,
FftwR2rKind kind0,
uint_t flags);
public static FftwPlan DftR2r2D(int n0, int n1, out FftwArray ioArray,
FftwR2rKind kind0, FftwR2rKind kind1, FftwFlags flags = FftwFlags.FFTW_MEASURE)
{
ioArray = new FftwArray(R2rLength(n0, n1, kind0, kind1));
return(DftR2r2D(n0, n1, ioArray, ioArray, kind0, kind1, flags));
}
private static int R2rLength(int n0, int n1, int n2, FftwR2rKind kind0, FftwR2rKind kind1, FftwR2rKind kind2) => R2rLength(n0, kind0) * R2rLength(n1, kind1) * R2rLength(n2, kind2);
