######################################################## Copyright (c) 2015, ArrayFire# All rights reserved.## This file is distributed under 3-clause BSD license.# The complete license agreement can be obtained at:# http://arrayfire.com/licenses/BSD-3-Clause########################################################"""Random engine class and functions to generate random numbers."""from.libraryimport*from.arrayimport*importnumbers
[docs]classRandom_Engine(object):"""    Class to handle random number generator engines.    Parameters    ----------    engine_type : optional: RANDOME_ENGINE. default: RANDOM_ENGINE.PHILOX                - Specifies the type of random engine to be created. Can be one of:                - RANDOM_ENGINE.PHILOX_4X32_10                - RANDOM_ENGINE.THREEFRY_2X32_16                - RANDOM_ENGINE.MERSENNE_GP11213                - RANDOM_ENGINE.PHILOX (same as RANDOM_ENGINE.PHILOX_4X32_10)                - RANDOM_ENGINE.THREEFRY (same as RANDOM_ENGINE.THREEFRY_2X32_16)                - RANDOM_ENGINE.DEFAULT                - Not used if engine is not None    seed        : optional int. default: 0                - Specifies the seed for the random engine                - Not used if engine is not None    engine      : optional ctypes.c_void_p. default: None.                - Used a handle created by the C api to create the Random_Engine.    """def__init__(self,engine_type=RANDOM_ENGINE.PHILOX,seed=0,engine=None):if(engineisNone):self.engine=c_void_ptr_t(0)safe_call(backend.get().af_create_random_engine(c_pointer(self.engine),engine_type.value,c_longlong_t(seed)))else:self.engine=enginedef__del__(self):safe_call(backend.get().af_release_random_engine(self.engine))
[docs]defset_type(self,engine_type):"""        Set the type of the random engine.        """safe_call(backend.get().af_random_engine_set_type(c_pointer(self.engine),engine_type.value))
[docs]defget_type(self):"""        Get the type of the random engine.        """__to_random_engine_type=[RANDOM_ENGINE.PHILOX_4X32_10,RANDOM_ENGINE.THREEFRY_2X32_16,RANDOM_ENGINE.MERSENNE_GP11213]rty=c_int_t(RANDOM_ENGINE.PHILOX.value)safe_call(backend.get().af_random_engine_get_type(c_pointer(rty),self.engine))return__to_random_engine_type[rty]
[docs]defset_seed(self,seed):"""        Set the seed for the random engine.        """safe_call(backend.get().af_random_engine_set_seed(c_pointer(self.engine),c_longlong_t(seed)))
[docs]defget_seed(self):"""        Get the seed for the random engine.        """seed=c_longlong_t(0)safe_call(backend.get().af_random_engine_get_seed(c_pointer(seed),self.engine))returnseed.value
[docs]defrandu(d0,d1=None,d2=None,d3=None,dtype=Dtype.f32,engine=None):"""    Create a multi dimensional array containing values from a uniform distribution.    Parameters    ----------    d0 : int.         Length of first dimension.    d1 : optional: int. default: None.         Length of second dimension.    d2 : optional: int. default: None.         Length of third dimension.    d3 : optional: int. default: None.         Length of fourth dimension.    dtype : optional: af.Dtype. default: af.Dtype.f32.           Data type of the array.    engine : optional: Random_Engine. default: None.             If engine is None, uses a default engine created by arrayfire.    Returns    -------    out : af.Array          Multi dimensional array whose elements are sampled uniformly between [0, 1].          - If d1 is None, `out` is 1D of size (d0,).          - If d1 is not None and d2 is None, `out` is 2D of size (d0, d1).          - If d1 and d2 are not None and d3 is None, `out` is 3D of size (d0, d1, d2).          - If d1, d2, d3 are all not None, `out` is 4D of size (d0, d1, d2, d3).    """out=Array()dims=dim4(d0,d1,d2,d3)ifengineisNone:safe_call(backend.get().af_randu(c_pointer(out.arr),4,c_pointer(dims),dtype.value))else:safe_call(backend.get().af_random_uniform(c_pointer(out.arr),4,c_pointer(dims),dtype.value,engine.engine))returnout
[docs]defrandn(d0,d1=None,d2=None,d3=None,dtype=Dtype.f32,engine=None):"""    Create a multi dimensional array containing values from a normal distribution.    Parameters    ----------    d0 : int.         Length of first dimension.    d1 : optional: int. default: None.         Length of second dimension.    d2 : optional: int. default: None.         Length of third dimension.    d3 : optional: int. default: None.         Length of fourth dimension.    dtype : optional: af.Dtype. default: af.Dtype.f32.           Data type of the array.    engine : optional: Random_Engine. default: None.             If engine is None, uses a default engine created by arrayfire.    Returns    -------    out : af.Array          Multi dimensional array whose elements are sampled from a normal distribution with mean 0 and sigma of 1.          - If d1 is None, `out` is 1D of size (d0,).          - If d1 is not None and d2 is None, `out` is 2D of size (d0, d1).          - If d1 and d2 are not None and d3 is None, `out` is 3D of size (d0, d1, d2).          - If d1, d2, d3 are all not None, `out` is 4D of size (d0, d1, d2, d3).    """out=Array()dims=dim4(d0,d1,d2,d3)ifengineisNone:safe_call(backend.get().af_randn(c_pointer(out.arr),4,c_pointer(dims),dtype.value))else:safe_call(backend.get().af_random_normal(c_pointer(out.arr),4,c_pointer(dims),dtype.value,engine.engine))returnout
[docs]defset_seed(seed=0):"""    Set the seed for the random number generator.    Parameters    ----------    seed: int.          Seed for the random number generator    """safe_call(backend.get().af_set_seed(c_ulonglong_t(seed)))
[docs]defget_seed():"""    Get the seed for the random number generator.    Returns    -------    seed: int.          Seed for the random number generator    """seed=c_ulonglong_t(0)safe_call(backend.get().af_get_seed(c_pointer(seed)))returnseed.value
[docs]defset_default_random_engine_type(engine_type):"""    Set random engine type for default random engine.    Parameters    ----------    engine_type : RANDOME_ENGINE.                - Specifies the type of random engine to be created. Can be one of:                - RANDOM_ENGINE.PHILOX_4X32_10                - RANDOM_ENGINE.THREEFRY_2X32_16                - RANDOM_ENGINE.MERSENNE_GP11213                - RANDOM_ENGINE.PHILOX (same as RANDOM_ENGINE.PHILOX_4X32_10)                - RANDOM_ENGINE.THREEFRY (same as RANDOM_ENGINE.THREEFRY_2X32_16)                - RANDOM_ENGINE.DEFAULT    Note    ----    This only affects randu and randn when a random engine is not specified.    """safe_call(backend.get().af_set_default_random_engine_type(c_pointer(self.engine),engine_type.value))
[docs]defget_default_random_engine():"""    Get the default random engine    Returns    -------    The default random engine used by randu and randn    """engine=c_void_ptr_t(0)default_engine=c_void_ptr_t(0)safe_call(backend.get().af_get_default_random_engine(c_pointer(default_engine)))safe_call(backend.get().af_retain_random_engine(c_pointer(engine),default_engine))returnRandom_Engine(engine=engine)