35 :
UnitTest (
"FFT", UnitTestCategories::dsp)
38 static void fillRandom (
Random& random, Complex<float>* buffer,
size_t n)
40 for (
size_t i = 0; i < n; ++i)
41 buffer[i] = Complex<float> ((2.0f * random.
nextFloat()) - 1.0f,
45 static void fillRandom (
Random& random,
float* buffer,
size_t n)
47 for (
size_t i = 0; i < n; ++i)
48 buffer[i] = (2.0f * random.
nextFloat()) - 1.0f;
51 static Complex<float> freqConvolution (
const Complex<float>* in,
float freq,
size_t n)
53 Complex<float> sum (0.0, 0.0);
54 for (
size_t i = 0; i < n; ++i)
55 sum += in[i] * exp (Complex<float> (0, static_cast<float> (i) * freq));
60 static void performReferenceFourier (
const Complex<float>* in, Complex<float>* out,
61 size_t n,
bool reverse)
64 / static_cast<float> (n));
66 for (
size_t i = 0; i < n; ++i)
67 out[i] = freqConvolution (in, static_cast<float>(i) * base_freq, n);
70 static void performReferenceFourier (
const float* in, Complex<float>* out,
71 size_t n,
bool reverse)
75 for (
size_t i = 0; i < n; ++i)
76 buffer.
getData()[i] = Complex<float> (in[i], 0.0f);
79 / static_cast<float> (n));
81 for (
size_t i = 0; i < n; ++i)
82 out[i] = freqConvolution (buffer.
getData(),
static_cast<float>(i) * base_freq, n);
87 template <
typename Type>
88 static bool checkArrayIsSimilar (Type* a, Type* b,
size_t n) noexcept
90 for (
size_t i = 0; i < n; ++i)
91 if (std::abs (a[i] - b[i]) > 1e-3f)
103 for (
size_t order = 0; order <= 8; ++order)
105 auto n = (1u << order);
107 FFT fft ((
int) order);
112 fillRandom (random, input.
getData(), n);
113 performReferenceFourier (input.
getData(), reference.getData(), n,
false);
116 zeromem (output.
getData(), n *
sizeof (Complex<float>));
117 memcpy (reinterpret_cast<float*> (output.
getData()), input.
getData(), n *
sizeof (float));
120 u.
expect (checkArrayIsSimilar (reference.getData(), output.
getData(), n));
123 zeromem (output.
getData(), n *
sizeof (Complex<float>));
124 memcpy (reinterpret_cast<float*> (output.
getData()), input.
getData(), n *
sizeof (float));
127 std::fill (reference.getData() + ((n >> 1) + 1), reference.getData() + n, std::complex<float> (0.0f));
128 u.
expect (checkArrayIsSimilar (reference.getData(), output.
getData(), (n >> 1) + 1));
130 memcpy (output.
getData(), reference.getData(), n *
sizeof (Complex<float>));
142 for (
size_t order = 0; order <= 8; ++order)
144 auto n = (1u << order);
146 FFT fft ((
int) order);
151 fillRandom (random, inout.getData(), n);
152 zeromem (reference.
getData(),
sizeof (float) * (n << 1));
153 performReferenceFourier (inout.getData(), frequency.
getData(), n,
false);
155 for (
size_t i = 0; i < n; ++i)
160 u.
expect (checkArrayIsSimilar (inout.getData(), reference.
getData(), n));
171 for (
size_t order = 0; order <= 7; ++order)
173 auto n = (1u << order);
175 FFT fft ((
int) order);
179 fillRandom (random, input.getData(), n);
180 performReferenceFourier (input.getData(), reference.
getData(), n,
false);
182 memcpy (buffer.getData(), input.getData(),
sizeof (Complex<float>) * n);
183 fft.
perform (buffer.getData(), output.getData(),
false);
185 u.
expect (checkArrayIsSimilar (output.getData(), reference.
getData(), n));
187 memcpy (buffer.getData(), reference.
getData(),
sizeof (Complex<float>) * n);
188 fft.
perform (buffer.getData(), output.getData(),
true);
191 u.
expect (checkArrayIsSimilar (output.getData(), input.getData(), n));
196 template <
class TheTest>
197 void runTestForAllTypes (
const char* unitTestName)
201 TheTest::run (*
this);
206 runTestForAllTypes<RealTest> (
"Real input numbers Test");
207 runTestForAllTypes<FrequencyOnlyTest> (
"Frequency only Test");
208 runTestForAllTypes<ComplexTest> (
"Complex input numbers Test");
void performFrequencyOnlyForwardTransform(float *inputOutputData) const noexcept
Takes an array and simply transforms it to the magnitude frequency response spectrum.
void perform(const Complex< float > *input, Complex< float > *output, bool inverse) const noexcept
Performs an out-of-place FFT, either forward or inverse.
ElementType * getData() const noexcept
Returns a raw pointer to the allocated data.
UnitTest(const String &name, const String &category=String())
Creates a test with the given name and optionally places it in a category.
Very simple container class to hold a pointer to some data on the heap.
void runTest() override
Implement this method in your subclass to actually run your tests.
This is a base class for classes that perform a unit test.
void beginTest(const String &testName)
Tells the system that a new subsection of tests is beginning.
void performRealOnlyInverseTransform(float *inputOutputData) const noexcept
Performs a reverse operation to data created in performRealOnlyForwardTransform().
Performs a fast fourier transform.
void expect(bool testResult, const String &failureMessage=String())
Checks that the result of a test is true, and logs this result.
void performRealOnlyForwardTransform(float *inputOutputData, bool dontCalculateNegativeFrequencies=false) const noexcept
Performs an in-place forward transform on a block of real data.
float nextFloat() noexcept
Returns the next random floating-point number.
A random number generator.
Commonly used mathematical constants.