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#include <stdio.h>
#include <time.h>
#include <stc/crandom.h>
#include <stc/cstr.h>
// Declare int -> int sorted map.
#define i_key int
#define i_val int
#include <stc/csmap.h>
int main()
{
enum {N = 10000000};
const double Mean = -12.0, StdDev = 6.0, Scale = 74;
printf("Demo of gaussian / normal distribution of %d random samples\n", N);
// Setup random engine with normal distribution.
uint64_t seed = (uint64_t)time(NULL);
stc64_t rng = stc64_new(seed);
stc64_normalf_t dist = stc64_normalf_new(Mean, StdDev);
// Create and init histogram map with defered destruct
csmap_int hist = {0};
cstr bar = {0};
c_forrange (N) {
int index = (int)round( stc64_normalf(&rng, &dist) );
csmap_int_insert(&hist, index, 0).ref->second += 1;
}
// Print the gaussian bar chart
c_forpair (index, count, csmap_int, hist) {
int n = (int)((float)*_.count * StdDev * Scale * 2.5f / (float)N);
if (n > 0) {
cstr_resize(&bar, n, '*');
printf("%4d %s\n", *_.index, cstr_str(&bar));
}
}
cstr_drop(&bar);
csmap_int_drop(&hist);
}
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