diff options
Diffstat (limited to 'libavutil/tests/lfg.c')
-rw-r--r-- | libavutil/tests/lfg.c | 165 |
1 files changed, 150 insertions, 15 deletions
diff --git a/libavutil/tests/lfg.c b/libavutil/tests/lfg.c index 9a0c47c4de..bf127e3031 100644 --- a/libavutil/tests/lfg.c +++ b/libavutil/tests/lfg.c @@ -1,18 +1,18 @@ /* - * This file is part of Libav. + * This file is part of FFmpeg. * - * Libav is free software; you can redistribute it and/or + * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * Libav is distributed in the hope that it will be useful, + * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with Libav; if not, write to the Free Software + * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ @@ -20,18 +20,96 @@ #include "libavutil/timer.h" #include "libavutil/lfg.h" +static const double Z_TABLE[31][10] = { + {0.5000, 0.5040, 0.5080, 0.5120, 0.5160, 0.5199, 0.5239, 0.5279, 0.5319, 0.5359}, + {0.5398, 0.5438, 0.5478, 0.5517, 0.5557, 0.5596, 0.5636, 0.5675, 0.5714, 0.5753}, + {0.5793, 0.5832, 0.5871, 0.5910, 0.5948, 0.5987, 0.6026, 0.6064, 0.6103, 0.6141}, + {0.6179, 0.6217, 0.6255, 0.6293, 0.6331, 0.6368, 0.6406, 0.6443, 0.6480, 0.6517}, + {0.6554, 0.6591, 0.6628, 0.6664, 0.6700, 0.6736, 0.6772, 0.6808, 0.6844, 0.6879}, + {0.6915, 0.6950, 0.6985, 0.7019, 0.7054, 0.7088, 0.7123, 0.7157, 0.7190, 0.7224}, + {0.7257, 0.7291, 0.7324, 0.7357, 0.7389, 0.7422, 0.7454, 0.7486, 0.7517, 0.7549}, + {0.7580, 0.7611, 0.7642, 0.7673, 0.7704, 0.7734, 0.7764, 0.7794, 0.7823, 0.7852}, + {0.7881, 0.7910, 0.7939, 0.7967, 0.7995, 0.8023, 0.8051, 0.8078, 0.8106, 0.8133}, + {0.8159, 0.8186, 0.8212, 0.8238, 0.8264, 0.8289, 0.8315, 0.8340, 0.8365, 0.8389}, + {0.8413, 0.8438, 0.8461, 0.8485, 0.8508, 0.8531, 0.8554, 0.8577, 0.8599, 0.8621}, + {0.8643, 0.8665, 0.8686, 0.8708, 0.8729, 0.8749, 0.8770, 0.8790, 0.8810, 0.8830}, + {0.8849, 0.8869, 0.8888, 0.8907, 0.8925, 0.8944, 0.8962, 0.8980, 0.8997, 0.9015}, + {0.9032, 0.9049, 0.9066, 0.9082, 0.9099, 0.9115, 0.9131, 0.9147, 0.9162, 0.9177}, + {0.9192, 0.9207, 0.9222, 0.9236, 0.9251, 0.9265, 0.9279, 0.9292, 0.9306, 0.9319}, + {0.9332, 0.9345, 0.9357, 0.9370, 0.9382, 0.9394, 0.9406, 0.9418, 0.9429, 0.9441}, + {0.9452, 0.9463, 0.9474, 0.9484, 0.9495, 0.9505, 0.9515, 0.9525, 0.9535, 0.9545}, + {0.9554, 0.9564, 0.9573, 0.9582, 0.9591, 0.9599, 0.9608, 0.9616, 0.9625, 0.9633}, + {0.9641, 0.9649, 0.9656, 0.9664, 0.9671, 0.9678, 0.9686, 0.9693, 0.9699, 0.9706}, + {0.9713, 0.9719, 0.9726, 0.9732, 0.9738, 0.9744, 0.9750, 0.9756, 0.9761, 0.9767}, + {0.9772, 0.9778, 0.9783, 0.9788, 0.9793, 0.9798, 0.9803, 0.9808, 0.9812, 0.9817}, + {0.9821, 0.9826, 0.9830, 0.9834, 0.9838, 0.9842, 0.9846, 0.9850, 0.9854, 0.9857}, + {0.9861, 0.9864, 0.9868, 0.9871, 0.9875, 0.9878, 0.9881, 0.9884, 0.9887, 0.9890}, + {0.9893, 0.9896, 0.9898, 0.9901, 0.9904, 0.9906, 0.9909, 0.9911, 0.9913, 0.9916}, + {0.9918, 0.9920, 0.9922, 0.9925, 0.9927, 0.9929, 0.9931, 0.9932, 0.9934, 0.9936}, + {0.9938, 0.9940, 0.9941, 0.9943, 0.9945, 0.9946, 0.9948, 0.9949, 0.9951, 0.9952}, + {0.9953, 0.9955, 0.9956, 0.9957, 0.9959, 0.9960, 0.9961, 0.9962, 0.9963, 0.9964}, + {0.9965, 0.9966, 0.9967, 0.9968, 0.9969, 0.9970, 0.9971, 0.9972, 0.9973, 0.9974}, + {0.9974, 0.9975, 0.9976, 0.9977, 0.9977, 0.9978, 0.9979, 0.9979, 0.9980, 0.9981}, + {0.9981, 0.9982, 0.9982, 0.9983, 0.9984, 0.9984, 0.9985, 0.9985, 0.9986, 0.9986}, + {0.9987, 0.9987, 0.9987, 0.9988, 0.9988, 0.9989, 0.9989, 0.9989, 0.9990, 0.9990} }; + +// Inverse cumulative distribution function +static double inv_cdf(double u) +{ + const double a[4] = { 2.50662823884, + -18.61500062529, + 41.39119773534, + -25.44106049637}; + + const double b[4] = {-8.47351093090, + 23.08336743743, + -21.06224101826, + 3.13082909833}; + + const double c[9] = {0.3374754822726147, + 0.9761690190917186, + 0.1607979714918209, + 0.0276438810333863, + 0.0038405729373609, + 0.0003951896511919, + 0.0000321767881768, + 0.0000002888167364, + 0.0000003960315187}; + + double r; + double x = u - 0.5; + + // Beasley-Springer + if (fabs(x) < 0.42) { + + double y = x * x; + r = x * (((a[3]*y+a[2])*y+a[1])*y+a[0]) / + ((((b[3]*y+b[2])*y+b[1])*y+b[0])*y+1.0); + } + else {// Moro + r = u; + if (x > 0.0) + r = 1.0 - u; + r = log(-log(r)); + r = c[0] + r*(c[1]+r*(c[2]+r*(c[3]+r*(c[4]+r*(c[5]+r*(c[6]+ + r*(c[7]+r*c[8]))))))); + if (x < 0.0) + r = -r; + } + + return r; +} int main(void) { int x = 0; int i, j; AVLFG state; - av_lfg_init(&state, 0xdeadbeef); for (j = 0; j < 10000; j++) { - START_TIMER - for (i = 0; i < 624; i++) + for (i = 0; i < 624; i++) { + //av_log(NULL, AV_LOG_ERROR, "%X\n", av_lfg_get(&state)); x += av_lfg_get(&state); - STOP_TIMER("624 calls of av_lfg_get"); + } } av_log(NULL, AV_LOG_ERROR, "final value:%X\n", x); @@ -39,18 +117,75 @@ int main(void) { double mean = 1000; double stddev = 53; + double samp_mean = 0.0, samp_stddev = 0.0, QH = 0; + double Z, p_value = -1, tot_samp = 1000; + double *PRN_arr = av_malloc_array(tot_samp, sizeof(double)); - av_lfg_init(&state, 42); + if (!PRN_arr) { + fprintf(stderr, "failed to allocate memory!\n"); + return 1; + } - for (i = 0; i < 1000; i += 2) { + av_lfg_init(&state, 42); + for (i = 0; i < tot_samp; i += 2) { double bmg_out[2]; av_bmg_get(&state, bmg_out); - av_log(NULL, AV_LOG_INFO, - "%f\n%f\n", - bmg_out[0] * stddev + mean, - bmg_out[1] * stddev + mean); + PRN_arr[i ] = bmg_out[0] * stddev + mean; + PRN_arr[i+1] = bmg_out[1] * stddev + mean; + samp_mean += PRN_arr[i] + PRN_arr[i+1]; + samp_stddev += PRN_arr[i] * PRN_arr[i] + PRN_arr[i+1] * PRN_arr[i+1]; + printf("PRN%d : %f\n" + "PRN%d : %f\n", + i, PRN_arr[i], i+1, PRN_arr[i+1]); + } + samp_mean /= tot_samp; + samp_stddev /= (tot_samp - 1); + samp_stddev -= (tot_samp * 1.0 / (tot_samp - 1))*samp_mean*samp_mean; + samp_stddev = sqrt(samp_stddev); + Z = (mean - samp_mean) / (stddev / sqrt(tot_samp)); + { + int x, y, a, b, flag = 0; + + if (Z < 0.0) { + flag = !flag; + Z = Z * -1.0; + } + + a = (int)(Z * 100); + b = ((int)Z * 100); + x = Z * 10; + y = (b > 0) ? a % b : a; + y = y % 10; + if (x > 30 || y > 9) { + av_log(NULL, AV_LOG_INFO, "error: out of bounds! tried to access" + "Z_TABLE[%d][%d]\n", x, y); + goto SKIP; + } + p_value = flag ? 1 - Z_TABLE[x][y] : Z_TABLE[x][y]; } - } +SKIP: for (i = 0; i < tot_samp; ++i) { + + if ( i < (tot_samp - 1)) { + double H_diff; + H_diff = inv_cdf((i + 2.0 - (3.0/8.0)) / (tot_samp + (1.0/4.0))); + H_diff -= inv_cdf((i + 1.0 - (3.0/8.0)) / (tot_samp + (1.0/4.0))); + + QH += ((PRN_arr[i + 1] - PRN_arr[i]) / H_diff); + } + } + QH = 1.0 - QH / ((tot_samp - 1.0) * samp_stddev); + + printf("sample mean : %f\n" + "true mean : %f\n" + "sample stddev: %f\n" + "true stddev : %f\n" + "z-score : %f\n" + "p-value : %f\n" + "QH[normality]: %f\n", + samp_mean, mean, samp_stddev, stddev, Z, p_value, QH); + + av_freep(&PRN_arr); + } return 0; } |