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Diffstat (limited to 'numpy/lib/getlimits.py')
| -rw-r--r-- | numpy/lib/getlimits.py | 175 |
1 files changed, 0 insertions, 175 deletions
diff --git a/numpy/lib/getlimits.py b/numpy/lib/getlimits.py deleted file mode 100644 index 00c3ea846..000000000 --- a/numpy/lib/getlimits.py +++ /dev/null @@ -1,175 +0,0 @@ -""" Machine limits for Float32 and Float64 and (long double) if available... -""" - -__all__ = ['finfo','iinfo'] - -from machar import MachAr -import numpy.core.numeric as numeric -import numpy.core.numerictypes as ntypes -from numpy.core.numeric import array -import numpy as N - -def _frz(a): - """fix rank-0 --> rank-1""" - if a.ndim == 0: a.shape = (1,) - return a - -_convert_to_float = { - ntypes.csingle: ntypes.single, - ntypes.complex_: ntypes.float_, - ntypes.clongfloat: ntypes.longfloat - } - -class finfo(object): - """Machine limits for floating point types. - - :Parameters: - dtype : floating point type or instance - - :SeeAlso: - - numpy.lib.machar.MachAr - - """ - - _finfo_cache = {} - - def __new__(cls, dtype): - obj = cls._finfo_cache.get(dtype,None) - if obj is not None: - return obj - dtypes = [dtype] - newdtype = numeric.obj2sctype(dtype) - if newdtype is not dtype: - dtypes.append(newdtype) - dtype = newdtype - if not issubclass(dtype, numeric.inexact): - raise ValueError, "data type %r not inexact" % (dtype) - obj = cls._finfo_cache.get(dtype,None) - if obj is not None: - return obj - if not issubclass(dtype, numeric.floating): - newdtype = _convert_to_float[dtype] - if newdtype is not dtype: - dtypes.append(newdtype) - dtype = newdtype - obj = cls._finfo_cache.get(dtype,None) - if obj is not None: - return obj - obj = object.__new__(cls)._init(dtype) - for dt in dtypes: - cls._finfo_cache[dt] = obj - return obj - - def _init(self, dtype): - self.dtype = dtype - if dtype is ntypes.double: - itype = ntypes.int64 - fmt = '%24.16e' - precname = 'double' - elif dtype is ntypes.single: - itype = ntypes.int32 - fmt = '%15.7e' - precname = 'single' - elif dtype is ntypes.longdouble: - itype = ntypes.longlong - fmt = '%s' - precname = 'long double' - else: - raise ValueError, repr(dtype) - - machar = MachAr(lambda v:array([v], dtype), - lambda v:_frz(v.astype(itype))[0], - lambda v:array(_frz(v)[0], dtype), - lambda v: fmt % array(_frz(v)[0], dtype), - 'numpy %s precision floating point number' % precname) - - for word in ['precision', 'iexp', - 'maxexp','minexp','negep', - 'machep']: - setattr(self,word,getattr(machar, word)) - for word in ['tiny','resolution','epsneg']: - setattr(self,word,getattr(machar, word).squeeze()) - self.max = machar.huge.flat[0] - self.min = -self.max - self.eps = machar.eps.flat[0] - self.nexp = machar.iexp - self.nmant = machar.it - self.machar = machar - self._str_tiny = machar._str_xmin - self._str_max = machar._str_xmax - self._str_epsneg = machar._str_epsneg - self._str_eps = machar._str_eps - self._str_resolution = machar._str_resolution - return self - - def __str__(self): - return '''\ -Machine parameters for %(dtype)s ---------------------------------------------------------------------- -precision=%(precision)3s resolution=%(_str_resolution)s -machep=%(machep)6s eps= %(_str_eps)s -negep =%(negep)6s epsneg= %(_str_epsneg)s -minexp=%(minexp)6s tiny= %(_str_tiny)s -maxexp=%(maxexp)6s max= %(_str_max)s -nexp =%(nexp)6s min= -max ---------------------------------------------------------------------- -''' % self.__dict__ - - -class iinfo: - """Limits for integer types. - - :Parameters: - type : integer type or instance - - """ - - _min_vals = {} - _max_vals = {} - - def __init__(self, type): - self.dtype = N.dtype(type) - self.kind = self.dtype.kind - self.bits = self.dtype.itemsize * 8 - self.key = "%s%d" % (self.kind, self.bits) - if not self.kind in 'iu': - raise ValueError("Invalid integer data type.") - - def min(self): - """Minimum value of given dtype.""" - if self.kind == 'u': - return 0 - else: - try: - val = iinfo._min_vals[self.key] - except KeyError: - val = int(-(1L << (self.bits-1))) - iinfo._min_vals[self.key] = val - return val - - min = property(min) - - def max(self): - """Maximum value of given dtype.""" - try: - val = iinfo._max_vals[self.key] - except KeyError: - if self.kind == 'u': - val = int((1L << self.bits) - 1) - else: - val = int((1L << (self.bits-1)) - 1) - iinfo._max_vals[self.key] = val - return val - - max = property(max) - -if __name__ == '__main__': - f = finfo(ntypes.single) - print 'single epsilon:',f.eps - print 'single tiny:',f.tiny - f = finfo(ntypes.float) - print 'float epsilon:',f.eps - print 'float tiny:',f.tiny - f = finfo(ntypes.longfloat) - print 'longfloat epsilon:',f.eps - print 'longfloat tiny:',f.tiny |