numpy.MachAr¶
-
class
numpy.
MachAr
(float_conv=<class 'float'>, int_conv=<class 'int'>, float_to_float=<class 'float'>, float_to_str=<function MachAr.<lambda>>, title='Python floating point number')[source]¶ Diagnosing machine parameters.
- Parameters
- float_convfunction, optional
Function that converts an integer or integer array to a float or float array. Default is
float
.- int_convfunction, optional
Function that converts a float or float array to an integer or integer array. Default is
int
.- float_to_floatfunction, 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_strfunction, 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
.
References
- 1
Press, Teukolsky, Vetterling and Flannery, “Numerical Recipes in C++,” 2nd ed, Cambridge University Press, 2002, p. 31.
- 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)
- ibeta