kfr

commit 6cda7d9087c74d7793b8d5f39c6866cef7ce94f5
parent 7a43865db8c766d8ca32e503b92a7bb8de03c422
Author: d.levin256@gmail.com <d.levin256@gmail.com>
Date:   Tue, 27 Jun 2023 20:29:31 +0100

Tukey window

Diffstat:
M
include/kfr/dsp/window.hpp
 | 
32
+++++++++++++++++++++++++++++++-
M
tests/unit/dsp/window.cpp
 | 
5
+++++

2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/include/kfr/dsp/window.hpp b/include/kfr/dsp/window.hpp
@@ -53,6 +53,7 @@ enum class window_type
     lanczos         = 14,
     cosine_np       = 15,
     planck_taper    = 16,
+    tukey           = 17,
 };
 
 template <window_type type>
@@ -398,6 +399,23 @@ struct expression_planck_taper : expression_window_with_metrics<T, window_metric
     }
 };
 
+template <typename T>
+struct expression_tukey : expression_window_with_metrics<T, window_metrics::metrics_m1_1>
+{
+    expression_tukey(size_t size, T epsilon, window_symmetry symmetry = window_symmetry::symmetric)
+        : expression_window_with_metrics<T, window_metrics::metrics_m1_1>(size, epsilon, symmetry)
+    {
+    }
+    template <size_t N>
+    KFR_INTRINSIC friend vec<T, N> get_elements(const expression_tukey& self, shape<1> index,
+                                                axis_params<0, N> sh)
+    {
+        vec<T, N> x   = (T(1) - abs(get_elements(self.linspace, index, sh))) / self.arg;
+        vec<T, N> val = T(0.5) * (T(1) - cos(c_pi<T> * x));
+        return select(x <= T(0), T(0), select(x >= T(1), T(1), val));
+    }
+};
+
 template <window_type>
 struct window_by_type;
 
@@ -424,6 +442,7 @@ KFR_WINDOW_BY_TYPE(gaussian)
 KFR_WINDOW_BY_TYPE(lanczos)
 KFR_WINDOW_BY_TYPE(cosine_np)
 KFR_WINDOW_BY_TYPE(planck_taper)
+KFR_WINDOW_BY_TYPE(tukey)
 #undef KFR_WINDOW_BY_TYPE
 
 /**
@@ -582,6 +601,17 @@ KFR_FUNCTION expression_planck_taper<T> window_planck_taper(
     return expression_planck_taper<T>(size, epsilon, symmetry);
 }
 
+/**
+ * @brief Returns template expression that generates Tukey window of length @c size (numpy compatible)
+ */
+template <typename T = fbase>
+KFR_FUNCTION expression_tukey<T> window_tukey(size_t size, identity<T> alpha,
+                                              window_symmetry symmetry = window_symmetry::symmetric,
+                                              ctype_t<T>               = ctype_t<T>())
+{
+    return expression_tukey<T>(size, alpha, symmetry);
+}
+
 template <typename T           = fbase, window_type type,
           typename window_expr = typename window_by_type<type>::template type<T>>
 CMT_NOINLINE window_expr window(size_t size, cval_t<window_type, type>, identity<T> win_param = T(),
@@ -601,7 +631,7 @@ CMT_NOINLINE expression_handle<T> window(size_t size, window_type type, identity
                 window_type::cosine, window_type::hann, window_type::bartlett_hann, window_type::hamming,
                 window_type::bohman, window_type::blackman, window_type::blackman_harris, window_type::kaiser,
                 window_type::flattop, window_type::gaussian, window_type::lanczos, window_type::cosine_np,
-                window_type::planck_taper>(),
+                window_type::planck_taper, window_type::tukey>(),
         type,
         [size, win_param, symmetry](auto win)
         {
diff --git a/tests/unit/dsp/window.cpp b/tests/unit/dsp/window.cpp
@@ -37,6 +37,7 @@ const char* wins[] = {
     "lanczos        ",
     "cosine_np      ",
     "planck_taper   ",
+    "tukey          ",
 };
 
 template <window_type type, typename T>
@@ -83,6 +84,7 @@ TEST(window)
     win<w::cosine_np, f32>(7, 0.0, s::symmetric,
                            u{ 0.22252093, 0.6234898, 0.90096887, 1., 0.90096887, 0.6234898, 0.22252093 });
     win<w::planck_taper, f32>(7, 0.25, s::symmetric, u{ 0, 0.817575, 1, 1, 1, 0.817574, 0 });
+    win<w::tukey, f32>(7, 0.5, s::symmetric, u{ 0., 0.75, 1., 1., 1., 0.75, 0. });
 
     // 8 ; symmetric
     win<w::rectangular, f32>(8, 0.0, s::symmetric, u{ 1, 1, 1, 1, 1, 1, 1, 1 });
@@ -124,6 +126,7 @@ TEST(window)
         8, 0.0, s::symmetric,
         u{ 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023, 0.19509032 });
     win<w::planck_taper, f32>(8, 0.25, s::symmetric, u{ 0, 0.641834, 1, 1, 1, 1, 0.641833, 0 });
+    win<w::tukey, f32>(8, 0.5, s::symmetric, u{ 0., 0.61126047, 1., 1., 1., 1., 0.61126047, 0. });
 
     // 7 ; periodic
     win<w::rectangular, f32>(7, 0.0, s::periodic, u{ 1, 1, 1, 1, 1, 1, 1 });
@@ -161,6 +164,7 @@ TEST(window)
         7, 0.0, s::periodic,
         u{ 0.19509032, 0.55557023, 0.83146961, 0.98078528, 0.98078528, 0.83146961, 0.55557023 });
     win<w::planck_taper, f32>(7, 0.25, s::periodic, u{ 0, 0.641834, 1, 1, 1, 1, 0.641833 });
+    win<w::tukey, f32>(7, 0.5, s::periodic, u{ 0., 0.61126047, 1., 1., 1., 1., 0.61126047 });
 
     // 8 ; periodic
     win<w::rectangular, f32>(8, 0.0, s::periodic, u{ 1, 1, 1, 1, 1, 1, 1, 1 });
@@ -196,6 +200,7 @@ TEST(window)
     win<w::cosine_np, f32>(8, 0.0, s::periodic,
                            u{ 0.17364818, 0.5, 0.76604444, 0.93969262, 1., 0.93969262, 0.76604444, 0.5 });
     win<w::planck_taper, f32>(8, 0.25, s::periodic, u{ 0, 0.5, 1, 1, 1, 1, 1, 0.5 });
+    win<w::tukey, f32>(8, 0.5, s::periodic, u{ 0., 0.5, 1., 1., 1., 1., 1., 0.5 });
     // clang-format on
 }
 } // namespace CMT_ARCH_NAME