1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
# Random number generators
This describes the API of module **crandom**.
## Types
| crandom | Type definition | Used to represent... |
|:----------------------|:-------------------------------------------|:-------------------------------------|
| `crand_rng32_t` | `struct {uint64_t state[2];}` | The crandom type |
| `crand_uniform_i32_t` | `struct {int32_t offset; uint32_t range;}` | The crandom element type |
| `crand_uniform_f32_t` | `struct {float offset, range;}` | crandom iterator |
| `crand_rng64_t` | `struct {uint64_t state[4];}` | |
| `crand_uniform_i64_t` | `struct {int64_t offset; uint64_t range;}` | |
| `crand_uniform_f64_t` | `struct {double offset, range;}` | |
| `crand_normal_f64_t` | `struct {double mean, stddev, next; bool has_next;}` | |
## Header file
All cstr definitions and prototypes may be included in your C source file by including a single header file.
```c
#include "stc/crandom.h"
```
## Methods
### Construction
Interfaces to create 32-bits random numbers:
```c
crand_rng32_t crand_rng32_with_seq(uint64_t seed, uint64_t seq);
crand_rng32_t crand_rng32_init(uint64_t seed);
uint32_t crand_i32(crand_rng32_t* rng); /* int random number generator, range [0, 2^32) */
float crand_f32(crand_rng32_t* rng);
crand_uniform_i32_t crand_uniform_i32_init(int32_t low, int32_t high); /* int generator in range [low, high] */
int32_t crand_uniform_i32(crand_rng32_t* rng, crand_uniform_i32_t* dist);
uint32_t crand_unbiased_i32(crand_rng32_t* rng, crand_uniform_i32_t* dist); /* https://github.com/lemire/fastrange */
crand_uniform_f32_t crand_uniform_f32_init(float low, float high); /* float random number in range [low, high). Note: 23 bit resolution. */
float crand_uniform_f32(crand_rng32_t* rng, crand_uniform_f32_t* dist);
```
Interfaces to create 64-bits random numbers:
```c
crand_rng64_t crand_rng64_with_seq(uint64_t seed, uint64_t seq); /* engine initializers */
crand_rng64_t crand_rng64_init(uint64_t seed);
uint64_t crand_i64(crand_rng64_t* rng); /* int generator, range [0, 2^64). PRNG copyright Tyge Løvset, NORCE Research, 2020 */
double crand_f64(crand_rng64_t* rng); /* double random number in range [low, high). 52 bit resolution. */
crand_uniform_i64_t crand_uniform_i64_init(int64_t low, int64_t high); /* int generator in range [low, high] */
int64_t crand_uniform_i64(crand_rng64_t* rng, crand_uniform_i64_t* dist);
crand_uniform_f64_t crand_uniform_f64_init(double low, double high);
double crand_uniform_f64(crand_rng64_t* rng, crand_uniform_f64_t* dist);
crand_normal_f64_t crand_normal_f64_init(double mean, double stddev);
double crand_normal_f64(crand_rng64_t* rng, crand_normal_f64_t* dist);
```
|
