1 files changed, 45 insertions, 0 deletions
diff --git a/log-fourier.hpp b/log-fourier.hpp
new file mode 100644
index 0000000..e232bd6
--- /dev/null
+++ b/log-fourier.hpp
@@ -0,0 +1,45 @@
+#pragma once
+#include "types.hpp"
+
+#include <cmath>
+#include <fftw3.h>
+#include <vector>
+#include <tuple>
+#include <gsl/gsl_sf_gamma.h>
+
+class LogarithmicFourierTransform {
+private:
+  Complex* a;
+  Complex* â;
+  fftw_plan a_to_â;
+  fftw_plan â_to_a;
+  unsigned N;
+  unsigned pad;
+  Real k;
+  Real Δτ;
+  Real τₛ;
+  Real ωₛ;
+  Real sₛ;
+public:
+  LogarithmicFourierTransform(unsigned N, Real k, Real Δτ, unsigned pad = 4);
+  ~LogarithmicFourierTransform();
+  Real τ(unsigned n) const;
+  Real ω(unsigned n) const;
+  Real t(unsigned n) const;
+  Real ν(unsigned n) const;
+  Real s(unsigned n) const;
+  std::vector<Complex> fourier(const std::vector<Real>& c, bool symmetric);
+  std::vector<Real> inverse(const std::vector<Complex>& ĉ);
+};
+
+std::string logFourierFile(std::string prefix, unsigned p, unsigned s, Real λ, Real τ₀, Real β, unsigned log2n, Real Δτ, Real k);
+
+void logFourierSave(const std::vector<Real>& C, const std::vector<Real>& R, const std::vector<Complex>& Ct, const std::vector<Complex>& Rt, unsigned p, unsigned s, Real λ, Real τ₀, Real β, unsigned log2n, Real Δτ, Real k);
+
+bool logFourierLoad(std::vector<Real>& C, std::vector<Real>& R, std::vector<Complex>& Ct, std::vector<Complex>& Rt, unsigned p, unsigned s, Real λ, Real τ₀, Real β, unsigned log2n, Real Δτ, Real k);
+
+std::tuple<std::vector<Complex>, std::vector<Complex>> RddfCtdfCt(LogarithmicFourierTransform& fft, const std::vector<Real>& C, const std::vector<Real>& R, unsigned p, unsigned s, Real λ);
+
+Real estimateZ(LogarithmicFourierTransform& fft, const std::vector<Real>& C, const std::vector<Complex>& Ct, const std::vector<Real>& R, const std::vector<Complex>& Rt, unsigned p, unsigned s, Real λ, Real τ₀, Real β);
+
+Real energy(const LogarithmicFourierTransform& fft, std::vector<Real>&  C, const std::vector<Real>& R, unsigned p, unsigned s, Real λ, Real β);