/// <summary>
/// Performs a complex-to-real inverse fast fourier transformation.
/// </summary>
/// <seealso cref="http://www.fftw.org/fftw3_doc/One_002dDimensional-DFTs-of-Real-Data.html#One_002dDimensional-DFTs-of-Real-Data"/>
/// <seealso cref="http://www.fftw.org/fftw3_doc/Multi_002dDimensional-DFTs-of-Real-Data.html#Multi_002dDimensional-DFTs-of-Real-Data"/>
public static void IFFT(IPinnedArray <Complex> input, IPinnedArray <double> output, PlannerFlags plannerFlags = PlannerFlags.Default, int nThreads = 1)
{
if ((plannerFlags & PlannerFlags.Estimate) == PlannerFlags.Estimate)
{
using (var plan = FftwPlanRC.Create(output, input, DftDirection.Backwards, plannerFlags, nThreads))
{
plan.Execute();
return;
}
}
using (var plan = FftwPlanRC.Create(output, input, DftDirection.Backwards, plannerFlags | PlannerFlags.WisdomOnly, nThreads))
{
if (plan != null)
{
plan.Execute();
return;
}
}
/// If with <see cref="PlannerFlags.WisdomOnly"/> no plan can be created
/// and <see cref="PlannerFlags.Estimate"/> is not specified, we use
/// a different buffer to avoid overwriting the input
using (var bufferContainer = _bufferPool.RequestBuffer(input.Length * Marshal.SizeOf <Complex>() + MemoryAlignment))
using (var buffer = new AlignedArrayComplex(bufferContainer.Buffer, MemoryAlignment, input.GetSize()))
using (var plan = FftwPlanRC.Create(output, buffer, DftDirection.Backwards, plannerFlags, nThreads))
{
input.CopyTo(plan.BufferComplex);
plan.Execute();
}
}
static void doBandPass(IPinnedArray <Complex> trans, int[] passIndexRange)
{
var j1 = passIndexRange[0];
var j2 = passIndexRange[1];
var lenPositive = trans.Length / 2 + trans.Length % 2;
//positive freq
for (int i = 0; i < j1; i++)
{
trans[i] = 0;
}
for (int i = j2 + 1; i < lenPositive; i++)
{
trans[i] = 0;
}
//negative freq
j1 = trans.Length - j1;
j2 = trans.Length - j2;
for (int i = lenPositive; i < j2; i++)
{
trans[i] = 0;
}
for (int i = j1 + 1; i < trans.Length; i++)
{
trans[i] = 0;
}
}
public static void CopyTo <T>(this IPinnedArray <T> src, IPinnedArray <T> dst, int srcIndex, int dstIndex, int count)
where T : struct
{
if (count < 0 || count > src.Length)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (count > dst.Length)
{
throw new ArgumentException(nameof(dst), "Destination is not large enough.");
}
if (srcIndex + count > src.Length)
{
throw new ArgumentOutOfRangeException(nameof(srcIndex));
}
if (dstIndex + count > src.Length)
{
throw new ArgumentOutOfRangeException(nameof(dstIndex));
}
int sizeOfT = Marshal.SizeOf <T>();
unsafe
{
void *pSrc = new IntPtr(src.Pointer.ToInt64() + srcIndex * sizeOfT).ToPointer();
void *pDst = new IntPtr(dst.Pointer.ToInt64() + dstIndex * sizeOfT).ToPointer();
System.Buffer.MemoryCopy(pSrc, pDst, (long)dst.Length * sizeOfT, (long)count * sizeOfT);
}
}
protected override void VerifyMinSize(IPinnedArray <double> bufferReal, IPinnedArray <Complex> bufferComplex, int[] n)
{
int sizeComplex;
int sizeReal = 1;
checked
{
for (int i = 0; i < n.Length - 1; i++)
{
sizeReal *= n[i];
}
sizeComplex = sizeReal * (n[n.Length - 1] / 2 + 1);
sizeReal *= n[n.Length - 1];
}
if (bufferReal.Length < sizeReal)
{
throw new ArgumentException($"{nameof(bufferReal)} is too small.");
}
if (bufferComplex.Length < sizeComplex)
{
throw new ArgumentException($"{nameof(bufferComplex)} is too small.");
}
}
/// <summary>
/// Initializes a new plan using the provided input and output buffers.
/// These buffers may be overwritten during initialization.
/// </summary>
public static FftwPlanRC Create(IPinnedArray <double> bufferReal, IPinnedArray <Complex> bufferComplex, DftDirection direction, PlannerFlags plannerFlags = PlannerFlags.Default, int nThreads = 1)
{
FftwPlanRC plan = new FftwPlanRC(bufferReal, bufferComplex, bufferReal.Rank, bufferReal.GetSize(), true, direction, plannerFlags, nThreads);
if (plan.IsZero)
{
return(null);
}
return(plan);
}
FftwPlanR2R(IPinnedArray <Double> input, IPinnedArray <Double> output, int rank, int[] n, bool verifyRankAndSize, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
: base(input, output, rank, n, verifyRankAndSize, direction, plannerFlags, 1)
{
//int[] ns = input.GetSize();
//lock (FftwInterop.Lock)
//{
// //_plan = FftwInterop.fftw_plan_r2r(rank,ns,input.Pointer,output.Pointer,direction,plannerFlags);
// _plan = GetPlan(rank, n, input.Pointer, output.Pointer, direction, plannerFlags);
//}
}
internal static FftwPlanRC Create(IPinnedArray <double> bufferReal, IPinnedArray <Complex> bufferComplex, int rank, int[] n, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
{
FftwPlanRC plan = new FftwPlanRC(bufferReal, bufferComplex, rank, n, false, direction, plannerFlags, nThreads);
if (plan.IsZero)
{
return(null);
}
return(plan);
}
internal static FftwPlanC2C Create(IPinnedArray <Complex> input, IPinnedArray <Complex> output, int rank, int[] n, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
{
FftwPlanC2C plan = new FftwPlanC2C(input, output, rank, n, false, direction, plannerFlags, nThreads);
if (plan.IsZero)
{
return(null);
}
return(plan);
}
/// <summary>
/// Initializes a new plan using the provided input and output buffers.
/// These buffers may be overwritten during initialization.
/// </summary>
public static FftwPlanC2C Create(IPinnedArray <Complex> input, IPinnedArray <Complex> output, DftDirection direction, PlannerFlags plannerFlags = PlannerFlags.Default, int nThreads = 1)
{
FftwPlanC2C plan = new FftwPlanC2C(input, output, input.Rank, input.GetSize(), true, direction, plannerFlags, nThreads);
if (plan.IsZero)
{
return(null);
}
return(plan);
}
protected override void VerifyMinSize(IPinnedArray <Complex> input, IPinnedArray <Complex> output, int[] n)
{
int size = Utils.GetTotalSize(n);
if (input.Length < size)
{
throw new ArgumentException($"{nameof(input)} is too small.");
}
if (output.Length < size)
{
throw new ArgumentException($"{nameof(output)} is too small.");
}
}
protected override void VerifyRankAndSize(IPinnedArray <Complex> input, IPinnedArray <Complex> output)
{
if (input.Rank != output.Rank)
{
throw new ArgumentException($"{nameof(input)} and {nameof(output)} must have the same rank and size.");
}
for (int i = 0; i < input.Rank; i++)
{
if (input.GetLength(i) != output.GetLength(i))
{
throw new ArgumentException($"{nameof(input)} and {nameof(output)} must have the same rank and size.");
}
}
}
public static int GetIndex <T>(this IPinnedArray <T> array, int[] indices)
where T : struct
{
if (indices.Length != array.Rank)
{
throw new ArgumentException($"Array of length {nameof(array.Rank)} = {array.Rank} expected.", nameof(indices));
}
int index = indices[0];
for (int i = 1; i < indices.Length; i++)
{
index *= array.GetLength(i);
index += indices[i];
}
return(index);
}
public static void CopyTo <T>(this IPinnedArray <T> src, IPinnedArray <T> dst, int[] srcIndices, int[] dstIndices, int count)
where T : struct
{
if (srcIndices == null)
{
throw new ArgumentNullException(nameof(srcIndices));
}
if (dstIndices == null)
{
throw new ArgumentNullException(nameof(dstIndices));
}
int srcIndex = src.GetIndex(srcIndices);
int dstIndex = dst.GetIndex(dstIndices);
src.CopyTo(dst, srcIndex, dstIndex, count);
}
static void doBandStop(IPinnedArray <Complex> trans, int[] passIndexRange)
{
var j1 = passIndexRange[0];
var j2 = passIndexRange[1];
var lenPositive = trans.Length / 2 + trans.Length % 2;
for (int i = j1; i <= j2; i++)
{
trans[i] = 0;
}
j1 = trans.Length - j1;
j2 = trans.Length - j2;
for (int i = j2; i <= j1; i++)
{
trans[i] = 0;
}
}
protected override void VerifyRankAndSize(IPinnedArray <double> bufferReal, IPinnedArray <Complex> bufferComplex)
{
if (bufferReal.Rank != bufferComplex.Rank)
{
throw new ArgumentException($"{nameof(bufferReal)} and {nameof(bufferComplex)} must have the same rank and size.");
}
for (int i = 0; i < bufferReal.Rank - 1; i++)
{
if (bufferReal.GetLength(i) != bufferComplex.GetLength(i))
{
throw new ArgumentException($"Lenght of {nameof(bufferComplex)} must be equal to n[0]*...*(n[n.Length - 1] / 2 + 1) with n being the size of {nameof(bufferReal)}.");
}
}
if (bufferReal.GetLength(bufferReal.Rank - 1) / 2 + 1 != bufferComplex.GetLength(bufferReal.Rank - 1))
{
throw new ArgumentException($"Lenght of {nameof(bufferComplex)} must be equal to n[0]*...*(n[n.Length - 1] / 2 + 1) with n being the size of {nameof(bufferReal)}.");
}
}
static void Transform(IPinnedArray <Complex> input, IPinnedArray <Complex> output, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
{
if ((plannerFlags & PlannerFlags.Estimate) == PlannerFlags.Estimate)
{
using (var plan = FftwPlanC2C.Create(input, output, direction, plannerFlags, nThreads))
{
plan.Execute();
return;
}
}
using (var plan = FftwPlanC2C.Create(input, output, direction, plannerFlags | PlannerFlags.WisdomOnly, nThreads))
{
if (plan != null)
{
plan.Execute();
return;
}
}
/// If with <see cref="PlannerFlags.WisdomOnly"/> no plan can be created
/// and <see cref="PlannerFlags.Estimate"/> is not specified, we use
/// a different buffer to avoid overwriting the input
if (input != output)
{
using (var plan = FftwPlanC2C.Create(output, output, input.Rank, input.GetSize(), direction, plannerFlags, nThreads))
{
input.CopyTo(output);
plan.Execute();
}
}
else
{
using (var bufferContainer = _bufferPool.RequestBuffer(input.Length * Marshal.SizeOf <Complex>() + MemoryAlignment))
using (var buffer = new AlignedArrayComplex(bufferContainer.Buffer, MemoryAlignment, input.GetSize()))
using (var plan = FftwPlanC2C.Create(buffer, buffer, input.Rank, input.GetSize(), direction, plannerFlags, nThreads))
{
input.CopyTo(plan.Input);
plan.Execute();
plan.Output.CopyTo(output, 0, 0, input.Length);
}
}
}
internal protected FftwPlan(IPinnedArray <T1> buffer1, IPinnedArray <T2> buffer2, int rank, int[] n, bool verifyRankAndSize, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
{
if (!FftwInterop.IsAvailable)
{
throw new InvalidOperationException($"{nameof(FftwInterop.IsAvailable)} returns false.");
}
if (buffer1.IsDisposed)
{
throw new ObjectDisposedException(nameof(buffer1));
}
if (buffer2.IsDisposed)
{
throw new ObjectDisposedException(nameof(buffer2));
}
if (verifyRankAndSize)
{
VerifyRankAndSize(buffer1, buffer2);
}
else
{
VerifyMinSize(buffer1, buffer2, n);
}
if (nThreads < 1)
{
nThreads = Environment.ProcessorCount;
}
_buffer1 = buffer1;
_buffer2 = buffer2;
_plan = IntPtr.Zero;
lock (FftwInterop.Lock)
{
FftwInterop.fftw_plan_with_nthreads(nThreads);
_plan = GetPlan(rank, n, _buffer1.Pointer, _buffer2.Pointer, direction, plannerFlags);
}
}
FftwPlanC2C(IPinnedArray <Complex> input, IPinnedArray <Complex> output, int rank, int[] n, bool verifyRankAndSize, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
: base(input, output, rank, n, verifyRankAndSize, direction, plannerFlags, nThreads)
{
}
protected abstract void VerifyRankAndSize(IPinnedArray <T1> input, IPinnedArray <T2> output);
/// <summary>
/// Performs a complex-to-complex inverse fast fourier transformation. The dimension is inferred from the input (<see cref="Array{T}.Rank"/>).
/// </summary>
/// <seealso cref="http://www.fftw.org/fftw3_doc/Complex-One_002dDimensional-DFTs.html#Complex-One_002dDimensional-DFTs"/>
/// <seealso cref="http://www.fftw.org/fftw3_doc/Complex-Multi_002dDimensional-DFTs.html#Complex-Multi_002dDimensional-DFTs"/>
public static void IFFT(IPinnedArray <Complex> input, IPinnedArray <Complex> output, PlannerFlags plannerFlags = PlannerFlags.Default, int nThreads = 1) => Transform(input, output, DftDirection.Backwards, plannerFlags, nThreads);
FftwPlanRC(IPinnedArray <double> bufferReal, IPinnedArray <Complex> bufferComplex, int rank, int[] n, bool verifyRankAndSize, DftDirection direction, PlannerFlags plannerFlags, int nThreads)
: base(bufferReal, bufferComplex, rank, n, verifyRankAndSize, direction, plannerFlags, nThreads)
{
}
public static void CopyTo <T>(this IPinnedArray <T> src, IPinnedArray <T> dst) where T : struct
{
src.CopyTo(dst, 0, 0, dst.Length);
}
protected abstract void VerifyMinSize(IPinnedArray <T1> ipput, IPinnedArray <T2> output, int[] n);
