diff --git a/stats.c b/stats.c new file mode 100644 index 0000000..4209365 --- /dev/null +++ b/stats.c @@ -0,0 +1,65 @@ +#include +#include +#include +#include + +Stats *Stats_recreate(double sum, double sumsq, unsigned long n, + double min, double max) +{ + Stats *st = malloc(sizeof(Stats)); + check_mem(st); + + st->sum = sum; + st->sumsq = sumsq; + st->n = n; + st->min = min; + st->max = max; + + return st; + +error: + return NULL; +} + +Stats *Stats_create() +{ + return Stats_recreate(0.0, 0.0, 0L, 0.0, 0.0); +} + +double Stats_mean(Stats * st) +{ + return st->sum / st->n; +} + +double Stats_stddev(Stats * st) +{ + return sqrt((st->sumsq - (st->sum * st->sum / st->n)) / + (st->n - 1)); +} + +void Stats_sample(Stats * st, double s) +{ + st->sum += s; + st->sumsq += s * s; + + if (st->n == 0) { + st->min = s; + st->max = s; + } else { + if (st->min > s) + st->min = s; + if (st->max < s) + st->max = s; + } + + st->n += 1; +} + +void Stats_dump(Stats * st) +{ + fprintf(stderr, + "sum: %f, sumsq: %f, n: %ld, " + "min: %f, max: %f, mean: %f, stddev: %f", + st->sum, st->sumsq, st->n, st->min, st->max, Stats_mean(st), + Stats_stddev(st)); +} diff --git a/stats.h b/stats.h new file mode 100644 index 0000000..95d3609 --- /dev/null +++ b/stats.h @@ -0,0 +1,25 @@ +#ifndef lcthw_stats_h +#define lcthw_stats_h + +typedef struct Stats { + double sum; + double sumsq; + unsigned long n; + double min; + double max; +} Stats; + +Stats *Stats_recreate(double sum, double sumsq, unsigned long n, + double min, double max); + +Stats *Stats_create(); + +double Stats_mean(Stats * st); + +double Stats_stddev(Stats * st); + +void Stats_sample(Stats * st, double s); + +void Stats_dump(Stats * st); + +#endif