diff tests/TestFFT.cpp @ 110:87ad66aaed32

FFT and window tests

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/TestFFT.cpp	Mon Sep 30 16:50:38 2013 +0100
@@ -0,0 +1,149 @@
+
+#include "dsp/transforms/FFT.h"
+
+#define BOOST_TEST_DYN_LINK
+#define BOOST_TEST_MAIN
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_AUTO_TEST_SUITE(TestFFT)
+
+#define COMPARE_CONST(a, n) \
+    for (int cmp_i = 0; cmp_i < (int)(sizeof(a)/sizeof(a[0])); ++cmp_i) { \
+        BOOST_CHECK_SMALL(a[cmp_i] - n, 1e-14);				\
+    }
+
+#define COMPARE_ARRAY(a, b)						\
+    for (int cmp_i = 0; cmp_i < (int)(sizeof(a)/sizeof(a[0])); ++cmp_i) { \
+        BOOST_CHECK_SMALL(a[cmp_i] - b[cmp_i], 1e-14);			\
+    }
+
+BOOST_AUTO_TEST_CASE(dc)
+{
+    // DC-only signal. The DC bin is purely real
+    double in[] = { 1, 1, 1, 1 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    BOOST_CHECK_EQUAL(re[0], 4.0);
+    BOOST_CHECK_EQUAL(re[1], 0.0);
+    BOOST_CHECK_EQUAL(re[2], 0.0);
+    COMPARE_CONST(im, 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+
+BOOST_AUTO_TEST_CASE(sine)
+{
+    // Sine. Output is purely imaginary
+    double in[] = { 0, 1, 0, -1 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    COMPARE_CONST(re, 0.0);
+    BOOST_CHECK_EQUAL(im[0], 0.0);
+    BOOST_CHECK_EQUAL(im[1], -2.0);
+    BOOST_CHECK_EQUAL(im[2], 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+
+BOOST_AUTO_TEST_CASE(cosine)
+{
+    // Cosine. Output is purely real
+    double in[] = { 1, 0, -1, 0 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    BOOST_CHECK_EQUAL(re[0], 0.0);
+    BOOST_CHECK_EQUAL(re[1], 2.0);
+    BOOST_CHECK_EQUAL(re[2], 0.0);
+    COMPARE_CONST(im, 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+	
+BOOST_AUTO_TEST_CASE(sineCosine)
+{
+    // Sine and cosine mixed
+    double in[] = { 0.5, 1, -0.5, -1 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    BOOST_CHECK_EQUAL(re[0], 0.0);
+    BOOST_CHECK_CLOSE(re[1], 1.0, 1e-12);
+    BOOST_CHECK_EQUAL(re[2], 0.0);
+    BOOST_CHECK_EQUAL(im[0], 0.0);
+    BOOST_CHECK_CLOSE(im[1], -2.0, 1e-12);
+    BOOST_CHECK_EQUAL(im[2], 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+
+BOOST_AUTO_TEST_CASE(nyquist)
+{
+    double in[] = { 1, -1, 1, -1 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    BOOST_CHECK_EQUAL(re[0], 0.0);
+    BOOST_CHECK_EQUAL(re[1], 0.0);
+    BOOST_CHECK_EQUAL(re[2], 4.0);
+    COMPARE_CONST(im, 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+
+BOOST_AUTO_TEST_CASE(dirac)
+{
+    double in[] = { 1, 0, 0, 0 };
+    double re[4], im[4];
+    FFT(4).process(false, in, 0, re, im);
+    BOOST_CHECK_EQUAL(re[0], 1.0);
+    BOOST_CHECK_EQUAL(re[1], 1.0);
+    BOOST_CHECK_EQUAL(re[2], 1.0);
+    COMPARE_CONST(im, 0.0);
+    double back[4];
+    double backim[4];
+    FFT(4).process(true, re, im, back, backim);
+    COMPARE_ARRAY(back, in);
+}
+
+BOOST_AUTO_TEST_CASE(forwardArrayBounds)
+{
+    // initialise bins to something recognisable, so we can tell
+    // if they haven't been written
+    double in[] = { 1, 1, -1, -1 };
+    double re[] = { 999, 999, 999, 999, 999, 999 };
+    double im[] = { 999, 999, 999, 999, 999, 999 };
+    FFT(4).process(false, in, 0, re+1, im+1);
+    // And check we haven't overrun the arrays
+    BOOST_CHECK_EQUAL(re[0], 999.0);
+    BOOST_CHECK_EQUAL(im[0], 999.0);
+    BOOST_CHECK_EQUAL(re[5], 999.0);
+    BOOST_CHECK_EQUAL(im[5], 999.0);
+}
+
+BOOST_AUTO_TEST_CASE(inverseArrayBounds)
+{
+    // initialise bins to something recognisable, so we can tell
+    // if they haven't been written
+    double re[] = { 0, 1, 0 };
+    double im[] = { 0, -2, 0 };
+    double outre[] = { 999, 999, 999, 999, 999, 999 };
+    double outim[] = { 999, 999, 999, 999, 999, 999 };
+    FFT(4).process(false, re, im, outre+1, outim+1);
+    // And check we haven't overrun the arrays
+    BOOST_CHECK_EQUAL(outre[0], 999.0);
+    BOOST_CHECK_EQUAL(outim[0], 999.0);
+    BOOST_CHECK_EQUAL(outre[5], 999.0);
+    BOOST_CHECK_EQUAL(outim[5], 999.0);
+}
+
+BOOST_AUTO_TEST_SUITE_END()
+