From eda5bc26f44ee9a6f83dcf8c91f17296d7fc509d Mon Sep 17 00:00:00 2001
From: Nao Pross <np@0hm.ch>
Date: Mon, 12 Feb 2024 14:52:43 +0100
Subject: Move into version control

---
 src/armadillo/include/armadillo_bits/fn_fft2.hpp | 136 +++++++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 src/armadillo/include/armadillo_bits/fn_fft2.hpp

(limited to 'src/armadillo/include/armadillo_bits/fn_fft2.hpp')

diff --git a/src/armadillo/include/armadillo_bits/fn_fft2.hpp b/src/armadillo/include/armadillo_bits/fn_fft2.hpp
new file mode 100644
index 0000000..51ea0da
--- /dev/null
+++ b/src/armadillo/include/armadillo_bits/fn_fft2.hpp
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: Apache-2.0
+// 
+// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
+// Copyright 2008-2016 National ICT Australia (NICTA)
+// 
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+// 
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+// ------------------------------------------------------------------------
+
+
+//! \addtogroup fn_fft2
+//! @{
+
+
+
+// 2D FFT & 2D IFFT
+
+
+
+template<typename T1>
+arma_warn_unused
+inline
+typename
+enable_if2
+  <
+  is_arma_type<T1>::value,
+  Mat< std::complex<typename T1::pod_type> >
+  >::result
+fft2(const T1& A)
+  {
+  arma_extra_debug_sigprint();
+  
+  // not exactly efficient, but "better-than-nothing" implementation
+  
+  typedef typename T1::pod_type T;
+  
+  Mat< std::complex<T> > B = fft(A);
+  
+  // for square matrices, strans() will work out that an inplace transpose can be done,
+  // hence we can potentially avoid creating a temporary matrix
+  
+  B = strans(B);
+  
+  return strans( fft(B) );
+  }
+
+
+
+template<typename T1>
+arma_warn_unused
+inline
+typename
+enable_if2
+  <
+  is_arma_type<T1>::value,
+  Mat< std::complex<typename T1::pod_type> >
+  >::result
+fft2(const T1& A, const uword n_rows, const uword n_cols)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const quasi_unwrap<T1> tmp(A);
+  const Mat<eT>&     B = tmp.M;
+  
+  const bool do_resize = (B.n_rows != n_rows) || (B.n_cols != n_cols);
+  
+  return (do_resize) ? fft2(resize(B,n_rows,n_cols)) : fft2(B);
+  }
+
+
+
+template<typename T1>
+arma_warn_unused
+inline
+typename
+enable_if2
+  <
+  (is_arma_type<T1>::value && (is_cx_float<typename T1::elem_type>::yes || is_cx_double<typename T1::elem_type>::yes)),
+  Mat< std::complex<typename T1::pod_type> >
+  >::result
+ifft2(const T1& A)
+  {
+  arma_extra_debug_sigprint();
+  
+  // not exactly efficient, but "better-than-nothing" implementation
+  
+  typedef typename T1::pod_type T;
+  
+  Mat< std::complex<T> > B = ifft(A);
+  
+  // for square matrices, strans() will work out that an inplace transpose can be done,
+  // hence we can potentially avoid creating a temporary matrix
+  
+  B = strans(B);
+  
+  return strans( ifft(B) );
+  }
+
+
+
+template<typename T1>
+arma_warn_unused
+inline
+typename
+enable_if2
+  <
+  (is_arma_type<T1>::value && (is_cx_float<typename T1::elem_type>::yes || is_cx_double<typename T1::elem_type>::yes)),
+  Mat< std::complex<typename T1::pod_type> >
+  >::result
+ifft2(const T1& A, const uword n_rows, const uword n_cols)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const quasi_unwrap<T1> tmp(A);
+  const Mat<eT>&     B = tmp.M;
+  
+  const bool do_resize = (B.n_rows != n_rows) || (B.n_cols != n_cols);
+  
+  return (do_resize) ? ifft2(resize(B,n_rows,n_cols)) : ifft2(B);
+  }
+
+
+
+//! @}
-- 
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