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lavu/lfg-test: add simple sample mean, stddev checks 

Also added a TODO to change to a proper normality test in the future.

Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Ganesh Ajjanagadde <gajjanag@gmail.com>
This commit is contained in:
Ganesh Ajjanagadde 2016-03-12 07:37:06 -05:00
parent bdc798cc8d
commit 0c33ceda91
1 changed files with 18 additions and 2 deletions
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20
libavutil/lfg.c
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@ -84,17 +84,33 @@ int main(void)
{
double mean = 1000;
double stddev = 53;
double samp_mean = 0.0, samp_stddev = 0.0;
double samp0, samp1;
av_lfg_init(&state, 42);
for (i = 0; i < 1000; i += 2) {
double bmg_out[2];
av_bmg_get(&state, bmg_out);
samp0 = bmg_out[0] * stddev + mean;
samp1 = bmg_out[1] * stddev + mean;
samp_mean += samp0 + samp1;
samp_stddev += samp0 * samp0 + samp1 * samp1;
av_log(NULL, AV_LOG_INFO,
"%f\n%f\n",
bmg_out[0] * stddev + mean,
bmg_out[1] * stddev + mean);
samp0,
samp1);
}
/* TODO: add proper normality test */
samp_mean /= 1000;
samp_stddev /= 999;
samp_stddev -= (1000.0/999.0)*samp_mean*samp_mean;
samp_stddev = sqrt(samp_stddev);
av_log(NULL, AV_LOG_INFO, "sample mean : %f\n"
"true mean : %f\n"
"sample stddev: %f\n"
"true stddev : %f\n",
samp_mean, mean, samp_stddev, stddev);
}
return 0;