git subrepo clone --branch=20.41.6 git@github.com:ETLCPP/etl.git components/etl

subrepo:
  subdir:   "components/etl"
  merged:   "be5537ec"
upstream:
  origin:   "git@github.com:ETLCPP/etl.git"
  branch:   "20.41.6"
  commit:   "be5537ec"
git-subrepo:
  version:  "0.4.9"
  origin:   "???"
  commit:   "???"

components/etl/test/test_rescale.cpp

@@ -0,0 +1,97 @@
+/******************************************************************************
+The MIT License(MIT)
+
+Embedded Template Library.
+https://github.com/ETLCPP/etl
+https://www.etlcpp.com
+
+Copyright(c) 2021 John Wellbelove
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files(the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and / or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions :
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+******************************************************************************/
+
+#include "unit_test_framework.h"
+
+#include "etl/rescale.h"
+
+#include <array>
+#include <algorithm>
+#include <math.h>
+
+namespace
+{
+  constexpr size_t Size = 10UL;
+
+  using CharIntRescale    = etl::rescale<char, int>;
+  using CharDoubleRescale = etl::rescale<char, double>;
+
+  struct Compare
+  {
+    bool operator ()(double lhs, double rhs) const
+    {
+      return fabs(lhs - rhs) < 1.0;
+    }
+  };
+
+  //***********************************
+  const std::array<char, Size> input1 =
+  {
+    10, 11, 12, 13, 14, 15, 16, 17, 18, 19
+  };
+
+  //***********************************
+  const std::array<int, Size> result1 =
+  {
+    40000, 40211, 40422, 40633, 40844, 41055, 41266, 41477, 41688, 41900
+  };
+
+  std::array<int, Size> output1;
+
+  const std::array<double, Size> result2 =
+  {
+    40000.0, 40211.0, 40422.0, 40633.0, 40844.0, 41055.0, 41266.0, 41477.0, 41688.0, 41900.0
+  };
+
+  std::array<double, Size> output2;
+
+  SUITE(test_rescale)
+  {
+    //*************************************************************************
+    TEST(test_char_int_rescale)
+    {
+      CharIntRescale rescale(10, 19, 40000, 41900);
+
+      std::transform(input1.begin(), input1.end(), output1.begin(), rescale);
+
+      bool isEqual = std::equal(output1.begin(), output1.end(), result1.begin());
+      CHECK(isEqual);
+    }
+
+    //*************************************************************************
+    TEST(test_char_double_rescale)
+    {
+      CharDoubleRescale rescale(10, 19, 40000.0, 41900.0);
+
+      std::transform(input1.begin(), input1.end(), output2.begin(), rescale);
+
+      bool isEqual = std::equal(output2.begin(), output2.end(), result2.begin(), Compare());
+      CHECK(isEqual);
+    }
+  };
+}