mirror of
https://github.com/ClickHouse/ClickHouse.git
synced 2024-12-11 08:52:06 +00:00
53 lines
2.0 KiB
Markdown
53 lines
2.0 KiB
Markdown
|
# PCG Random Number Generation, C++ Edition
|
||
|
|
|
||
|
|
[PCG-Random website]: http://www.pcg-random.org
|
||
|
|
|
||
|
|
This code provides an implementation of the PCG family of random number
|
||
|
|
generators, which are fast, statistically excellent, and offer a number of
|
||
|
|
useful features.
|
||
|
|
|
||
|
|
Full details can be found at the [PCG-Random website]. This version
|
||
|
|
of the code provides many family members -- if you just want one
|
||
|
|
simple generator, you may prefer the minimal C version of the library.
|
||
|
|
|
||
|
|
There are two kinds of generator, normal generators and extended generators.
|
||
|
|
Extended generators provide *k* dimensional equidistribution and can perform
|
||
|
|
party tricks, but generally speaking most people only need the normal
|
||
|
|
generators.
|
||
|
|
|
||
|
|
There are two ways to access the generators, using a convenience typedef
|
||
|
|
or by using the underlying templates directly (similar to C++11's `std::mt19937` typedef vs its `std::mersenne_twister_engine` template). For most users, the convenience typedef is what you want, and probably you're fine with `pcg32` for 32-bit numbers. If you want 64-bit numbers, either use `pcg64` (or, if you're on a 32-bit system, making 64 bits from two calls to `pcg32_k2` may be faster).
|
||
|
|
|
||
|
|
## Documentation and Examples
|
||
|
|
|
||
|
|
Visit [PCG-Random website] for information on how to use this library, or look
|
||
|
|
at the sample code in the `sample` directory -- hopefully it should be fairly
|
||
|
|
self explanatory.
|
||
|
|
|
||
|
|
## Building
|
||
|
|
|
||
|
|
The code is written in C++11, as an include-only library (i.e., there is
|
||
|
|
nothing you need to build). There are some provided demo programs and tests
|
||
|
|
however. On a Unix-style system (e.g., Linux, Mac OS X) you should be able
|
||
|
|
to just type
|
||
|
|
|
||
|
|
make
|
||
|
|
|
||
|
|
To build the demo programs.
|
||
|
|
|
||
|
|
## Testing
|
||
|
|
|
||
|
|
Run
|
||
|
|
|
||
|
|
make test
|
||
|
|
|
||
|
|
## Directory Structure
|
||
|
|
|
||
|
|
The directories are arranged as follows:
|
||
|
|
|
||
|
|
* `include` -- contains `pcg_random.hpp` and supporting include files
|
||
|
|
* `test-high` -- test code for the high-level API where the functions have
|
||
|
|
shorter, less scary-looking names.
|
||
|
|
* `sample` -- sample code, some similar to the code in `test-high` but more
|
||
|
|
human readable, some other examples too
|