B F0d?*@sZdZdgZddlmZddlmZddlmZedGdddZe dkrVe ed S) z Machine arithmetics - determine the parameters of the floating-point arithmetic system Author: Pearu Peterson, September 2003 MachAr)any)errstate) set_modulenumpyc@s8eZdZdZeeedddfddZddZd d Zd S) ra Diagnosing machine parameters. Attributes ---------- ibeta : int Radix in which numbers are represented. it : int Number of base-`ibeta` digits in the floating point mantissa M. machep : int Exponent of the smallest (most negative) power of `ibeta` that, added to 1.0, gives something different from 1.0 eps : float Floating-point number ``beta**machep`` (floating point precision) negep : int Exponent of the smallest power of `ibeta` that, subtracted from 1.0, gives something different from 1.0. epsneg : float Floating-point number ``beta**negep``. iexp : int Number of bits in the exponent (including its sign and bias). minexp : int Smallest (most negative) power of `ibeta` consistent with there being no leading zeros in the mantissa. xmin : float Floating-point number ``beta**minexp`` (the smallest [in magnitude] positive floating point number with full precision). maxexp : int Smallest (positive) power of `ibeta` that causes overflow. xmax : float ``(1-epsneg) * beta**maxexp`` (the largest [in magnitude] usable floating value). irnd : int In ``range(6)``, information on what kind of rounding is done in addition, and on how underflow is handled. ngrd : int Number of 'guard digits' used when truncating the product of two mantissas to fit the representation. epsilon : float Same as `eps`. tiny : float Same as `xmin`. huge : float Same as `xmax`. precision : float ``- int(-log10(eps))`` resolution : float ``- 10**(-precision)`` Parameters ---------- float_conv : function, optional Function that converts an integer or integer array to a float or float array. Default is `float`. int_conv : function, optional Function that converts a float or float array to an integer or integer array. Default is `int`. float_to_float : function, optional Function that converts a float array to float. Default is `float`. Note that this does not seem to do anything useful in the current implementation. float_to_str : function, optional Function that converts a single float to a string. Default is ``lambda v:'%24.16e' %v``. title : str, optional Title that is printed in the string representation of `MachAr`. See Also -------- finfo : Machine limits for floating point types. iinfo : Machine limits for integer types. References ---------- .. [1] Press, Teukolsky, Vetterling and Flannery, "Numerical Recipes in C++," 2nd ed, Cambridge University Press, 2002, p. 31. cCsd|S)Nz%24.16e)vrrC/var/www/html/venv/lib/python3.7/site-packages/numpy/core/machar.pydzMachAr.zPython floating point numberc Cs,tdd||||||WdQRXdS)a! float_conv - convert integer to float (array) int_conv - convert float (array) to integer float_to_float - convert float array to float float_to_str - convert array float to str title - description of used floating point numbers ignore)ZunderN)r_do_init)self float_convint_convfloat_to_float float_to_strtitlerrr __init__bs zMachAr.__init__c.Csd}d}|d}||} ||} |} xLt|D].} | | } | |} | | }t||| kr.Pq.Wt|| |jf|}xLt|D].} ||}| |} || | }t|dkrPqWt|| |jf|}||}d}|}xTt|D]6} |d}||}||} | |}t||| krPqWt|| |jf|| }|} xPt|D]2} | | } | |} | | }t||| krDPqDWt|| |jf| |} d}t| | | krd}| |}||} |dkrt| || krd}|d}||}|} xt|D]}| |} qW| }xht|D]J} || } t| || kr %s )!ranger RuntimeErrorZdtypelocalsabsibetaitnegepepsnegZ _str_epsnegmachepepsZ_str_epsngrdiexpminexpxminZ _str_xminmaxexpxmaxZ _str_xmaxirndrepsilonZtinyZhugemathintlog10 precision resolutionZ_str_resolution).rrrrrrZ max_iterNmsgonetwozeroa_tempZtemp1bZitemprbetar Zbetahr+Ztempar!Zbetainir"r#r$r%kztZnxresyr&ZmxZizr(r'r)r*jr-tenr1rrr r ts\     $    $                 zMachAr._do_initcCsd}||jS)NaMachine parameters for %(title)s --------------------------------------------------------------------- ibeta=%(ibeta)s it=%(it)s iexp=%(iexp)s ngrd=%(ngrd)s irnd=%(irnd)s machep=%(machep)s eps=%(_str_eps)s (beta**machep == epsilon) negep =%(negep)s epsneg=%(_str_epsneg)s (beta**epsneg) minexp=%(minexp)s xmin=%(_str_xmin)s (beta**minexp == tiny) maxexp=%(maxexp)s xmax=%(_str_xmax)s ((1-epsneg)*beta**maxexp == huge) --------------------------------------------------------------------- )__dict__)rfmtrrr __str__Gs zMachAr.__str__N) __name__ __module__ __qualname____doc__floatr.rr rDrrrr rsP T__main__N) rH__all__Znumpy.core.fromnumericrZnumpy.core._ufunc_configrZnumpy.core.overridesrrrEprintrrrr s   G