commit 4a113bc1919de01ec0562f7c42455f1bf5cc0947
Author: Mark Borgerding <mark@borgerding.net>
Date:   Sat Aug 9 00:59:17 2003 +0000

    Initial revision

diff --git a/test.oct b/test.oct
new file mode 100755
index 0000000..b738a62
--- /dev/null
+++ b/test.oct
@@ -0,0 +1,64 @@
+#!/usr/bin/octave -q
+
+# Compare the results of kiss_fft with those calculated by octave's fft routines
+
+nfft=1024;
+showdiff=0;
+
+for test_case =1:3
+    printf( '====================================\n');
+    if test_case == 1,
+        prec = 'short'
+        prog = './kiss_fft_s'
+        scale = nfft
+    elseif test_case  == 2,
+        prec = 'float'
+        prog = './kiss_fft_f'
+        scale = 1
+    else
+        prec = 'double'
+        prog = './kiss_fft_d'
+        scale = 1
+    endif
+
+    # create the input
+    input = rand(1,nfft) .* exp(2*pi*j*rand(1,nfft));
+    input = floor( real(input)*32767 ) + j*floor(imag(input)*32767 );
+
+    # write the input
+    f = fopen( "fftin.dat", "w", "native");
+    to_write = [real(input);imag(input) ];
+    fwrite(f,to_write,prec);
+    fclose(f);
+
+    cmd = sprintf('%s %d < fftin.dat > fftout.dat',prog,nfft)
+    system(cmd);
+
+    # read the output
+    f = fopen("fftout.dat","r", "native");
+    from_read = fread(f,Inf,prec)';
+    output = (from_read(1:2:nfft*2) + j*from_read(2:2:nfft*2))        ;
+
+    comp = fft(input)/scale;
+    if test_case == 1,
+        comp = floor( real(comp) +.5) + j*floor( imag(comp) +.5);
+    endif
+
+    if showdiff,
+        x=linspace(0,2*pi,nfft);
+        figure(1);
+        plot( x, real(output), x, real(comp) );
+        figure(2);
+        plot( x, imag(output), x, imag(comp) );
+        figure(3);
+        plot( x, abs(output-comp) );
+        pause
+    else
+        diff = output - comp;
+        noise_pow =  sum( conj(diff).*diff );
+        sig_pow = sum( conj(comp).*comp );
+        snr = 10*log10( sig_pow / noise_pow )
+
+        avg_scale = mean(  abs(output) ./ abs(comp) )
+    endif
+endfor