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Python numeric.dtype函数代码示例

原作者: [db:作者] 来自: [db:来源] 收藏 邀请

本文整理汇总了Python中numeric.dtype函数的典型用法代码示例。如果您正苦于以下问题:Python dtype函数的具体用法?Python dtype怎么用?Python dtype使用的例子?那么恭喜您, 这里精选的函数代码示例或许可以为您提供帮助。



在下文中一共展示了dtype函数的16个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于我们的系统推荐出更棒的Python代码示例。

示例1: __new__

    def __new__(cls, dtype):
        try:
            dtype = numeric.dtype(dtype)
        except TypeError:
            # In case a float instance was given
            dtype = numeric.dtype(type(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
开发者ID:1950,项目名称:sawbuck,代码行数:32,代码来源:getlimits.py


示例2: __init__

 def __init__(self, int_type):
     try:
         self.dtype = numeric.dtype(int_type)
     except TypeError:
         self.dtype = numeric.dtype(type(int_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.")
开发者ID:1950,项目名称:sawbuck,代码行数:10,代码来源:getlimits.py


示例3: __new__

    def __new__(
        subtype,
        shape,
        dtype=None,
        buf=None,
        offset=0,
        strides=None,
        formats=None,
        names=None,
        titles=None,
        byteorder=None,
        aligned=False,
        order="C",
    ):

        if dtype is not None:
            descr = sb.dtype(dtype)
        else:
            descr = format_parser(formats, names, titles, aligned, byteorder)._descr

        if buf is None:
            self = ndarray.__new__(subtype, shape, (record, descr), order=order)
        else:
            self = ndarray.__new__(
                subtype, shape, (record, descr), buffer=buf, offset=offset, strides=strides, order=order
            )
        return self
开发者ID:songmm19900210,项目名称:galaxy-tools-prok,代码行数:27,代码来源:records.py


示例4: _parseFormats

    def _parseFormats(self, formats, aligned=0):
        """ Parse the field formats """

        if formats is None:
            raise ValueError, "Need formats argument"
        if isinstance(formats, list):
            if len(formats) < 2:
                formats.append('')
            formats = ','.join(formats)
        dtype = sb.dtype(formats, aligned)
        fields = dtype.fields
        if fields is None:
            dtype = sb.dtype([('f1', dtype)], aligned)
            fields = dtype.fields
        keys = dtype.names
        self._f_formats = [fields[key][0] for key in keys]
        self._offsets = [fields[key][1] for key in keys]
        self._nfields = len(keys)
开发者ID:258073127,项目名称:MissionPlanner,代码行数:18,代码来源:records.py


示例5: _createdescr

    def _createdescr(self, byteorder):
        descr = sb.dtype(
            {"names": self._names, "formats": self._f_formats, "offsets": self._offsets, "titles": self._titles}
        )
        if byteorder is not None:
            byteorder = _byteorderconv[byteorder[0]]
            descr = descr.newbyteorder(byteorder)

        self._descr = descr
开发者ID:songmm19900210,项目名称:galaxy-tools-prok,代码行数:9,代码来源:records.py


示例6: _createdescr

    def _createdescr(self, byteorder):
        descr = sb.dtype({'names':self._names,
                          'formats':self._f_formats,
                          'offsets':self._offsets,
                          'titles':self._titles})
        if (byteorder is not None):
            byteorder = _byteorderconv[byteorder[0]]
            descr = descr.newbyteorder(byteorder)

        self._descr = descr
开发者ID:258073127,项目名称:MissionPlanner,代码行数:10,代码来源:records.py


示例7: view

 def view(self, obj):
     try:
         if issubclass(obj, ndarray):
             return ndarray.view(self, obj)
     except TypeError:
         pass
     dtype = sb.dtype(obj)
     if dtype.fields is None:
         return self.__array__().view(dtype)
     return ndarray.view(self, obj)
开发者ID:8848,项目名称:Pymol-script-repo,代码行数:10,代码来源:records.py


示例8: view

 def view(self, dtype=None, type=None):
     if dtype is None:
         return ndarray.view(self, type)
     elif type is None:
         try:
             if issubclass(dtype, ndarray):
                 return ndarray.view(self, dtype)
         except TypeError:
             pass
         dtype = sb.dtype(dtype)
         if dtype.fields is None:
             return self.__array__().view(dtype)
         return ndarray.view(self, dtype)
     else:
         return ndarray.view(self, dtype, type)
开发者ID:258073127,项目名称:MissionPlanner,代码行数:15,代码来源:records.py


示例9: __new__

    def __new__(subtype, data, dtype=None, copy=True):
        if isinstance(data, matrix):
            dtype2 = data.dtype
            if (dtype is None):
                dtype = dtype2
            if (dtype2 == dtype) and (not copy):
                return data
            return data.astype(dtype)

        if isinstance(data, N.ndarray):
            if dtype is None:
                intype = data.dtype
            else:
                intype = N.dtype(dtype)
            new = data.view(subtype)
            if intype != data.dtype:
                return new.astype(intype)
            if copy: return new.copy()
            else: return new

        if isinstance(data, str):
            data = _convert_from_string(data)

        # now convert data to an array
        arr = N.array(data, dtype=dtype, copy=copy)
        ndim = arr.ndim
        shape = arr.shape
        if (ndim > 2):
            raise ValueError, "matrix must be 2-dimensional"
        elif ndim == 0:
            shape = (1,1)
        elif ndim == 1:
            shape = (1,shape[0])

        order = False
        if (ndim == 2) and arr.flags.fortran:
            order = True

        if not (order or arr.flags.contiguous):
            arr = arr.copy()

        ret = N.ndarray.__new__(subtype, shape, arr.dtype,
                                buffer=arr,
                                order=order)
        return ret
开发者ID:8848,项目名称:Pymol-script-repo,代码行数:45,代码来源:defmatrix.py


示例10: _init

    def _init(self, dtype):
        self.dtype = numeric.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'
        elif dtype is ntypes.half:
            itype = ntypes.int16
            fmt = '%12.5e'
            precname = 'half'
        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).flat[0])
        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.strip()
        self._str_max = machar._str_xmax.strip()
        self._str_epsneg = machar._str_epsneg.strip()
        self._str_eps = machar._str_eps.strip()
        self._str_resolution = machar._str_resolution.strip()
        return self
开发者ID:1950,项目名称:sawbuck,代码行数:45,代码来源:getlimits.py


示例11: _init

    def _init(self, dtype):
        self.dtype = numeric.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"
        elif dtype is ntypes.half:
            itype = ntypes.int16
            fmt = "%12.5e"
            precname = "half"
        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).flat[0])
        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.strip()
        self._str_max = machar._str_xmax.strip()
        self._str_epsneg = machar._str_epsneg.strip()
        self._str_eps = machar._str_eps.strip()
        self._str_resolution = machar._str_resolution.strip()
        return self
开发者ID:Xatpy,项目名称:echomesh,代码行数:45,代码来源:getlimits.py


示例12: fromstring

def fromstring(datastring, dtype=None, shape=None, offset=0, formats=None,
               names=None, titles=None, aligned=False, byteorder=None):
    """ create a (read-only) record array from binary data contained in
    a string"""


    if dtype is None and formats is None:
        raise ValueError, "Must have dtype= or formats="

    if dtype is not None:
        descr = sb.dtype(dtype)
    else:
        descr = format_parser(formats, names, titles, aligned, byteorder)._descr

    itemsize = descr.itemsize
    if (shape is None or shape == 0 or shape == -1):
        shape = (len(datastring) - offset) / itemsize

    _array = recarray(shape, descr, buf=datastring, offset=offset)
    return _array
开发者ID:258073127,项目名称:MissionPlanner,代码行数:20,代码来源:records.py


示例13: array

def array(obj, dtype=None, shape=None, offset=0, strides=None, formats=None,
          names=None, titles=None, aligned=False, byteorder=None, copy=True):
    """Construct a record array from a wide-variety of objects.
    """

    if (isinstance(obj, (type(None), str)) or isfileobj(obj)) \
           and (formats is None) \
           and (dtype is None):
        raise ValueError("Must define formats (or dtype) if object is "\
                         "None, string, or an open file")

    kwds = {}
    if dtype is not None:
        dtype = sb.dtype(dtype)
    elif formats is not None:
        dtype = format_parser(formats, names, titles,
                              aligned, byteorder)._descr
    else:
        kwds = {'formats': formats,
                'names' : names,
                'titles' : titles,
                'aligned' : aligned,
                'byteorder' : byteorder
                }

    if obj is None:
        if shape is None:
            raise ValueError("Must define a shape if obj is None")
        return recarray(shape, dtype, buf=obj, offset=offset, strides=strides)

    elif isinstance(obj, bytes):
        return fromstring(obj, dtype, shape=shape, offset=offset, **kwds)

    elif isinstance(obj, (list, tuple)):
        if isinstance(obj[0], (tuple, list)):
            return fromrecords(obj, dtype=dtype, shape=shape, **kwds)
        else:
            return fromarrays(obj, dtype=dtype, shape=shape, **kwds)

    elif isinstance(obj, recarray):
        if dtype is not None and (obj.dtype != dtype):
            new = obj.view(dtype)
        else:
            new = obj
        if copy:
            new = new.copy()
        return new

    elif isfileobj(obj):
        return fromfile(obj, dtype=dtype, shape=shape, offset=offset)

    elif isinstance(obj, ndarray):
        if dtype is not None and (obj.dtype != dtype):
            new = obj.view(dtype)
        else:
            new = obj
        if copy:
            new = new.copy()
        res = new.view(recarray)
        if issubclass(res.dtype.type, nt.void):
            res.dtype = sb.dtype((record, res.dtype))
        return res

    else:
        interface = getattr(obj, "__array_interface__", None)
        if interface is None or not isinstance(interface, dict):
            raise ValueError("Unknown input type")
        obj = sb.array(obj)
        if dtype is not None and (obj.dtype != dtype):
            obj = obj.view(dtype)
        res = obj.view(recarray)
        if issubclass(res.dtype.type, nt.void):
            res.dtype = sb.dtype((record, res.dtype))
        return res
开发者ID:258073127,项目名称:MissionPlanner,代码行数:74,代码来源:records.py


示例14: fromfile

def fromfile(fd, dtype=None, shape=None, offset=0, formats=None,
             names=None, titles=None, aligned=False, byteorder=None):
    """Create an array from binary file data

    If file is a string then that file is opened, else it is assumed
    to be a file object.

    >>> from tempfile import TemporaryFile
    >>> a = np.empty(10,dtype='f8,i4,a5')
    >>> a[5] = (0.5,10,'abcde')
    >>>
    >>> fd=TemporaryFile()
    >>> a = a.newbyteorder('<')
    >>> a.tofile(fd)
    >>>
    >>> fd.seek(0)
    >>> r=np.core.records.fromfile(fd, formats='f8,i4,a5', shape=10,
    ... byteorder='<')
    >>> print r[5]
    (0.5, 10, 'abcde')
    >>> r.shape
    (10,)
    """

    if (shape is None or shape == 0):
        shape = (-1,)
    elif isinstance(shape, (int, long)):
        shape = (shape,)

    name = 0
    if isinstance(fd, str):
        name = 1
        fd = open(fd, 'rb')
    if (offset > 0):
        fd.seek(offset, 1)
    size = get_remaining_size(fd)

    if dtype is not None:
        descr = sb.dtype(dtype)
    else:
        descr = format_parser(formats, names, titles, aligned, byteorder)._descr

    itemsize = descr.itemsize

    shapeprod = sb.array(shape).prod()
    shapesize = shapeprod * itemsize
    if shapesize < 0:
        shape = list(shape)
        shape[ shape.index(-1) ] = size / -shapesize
        shape = tuple(shape)
        shapeprod = sb.array(shape).prod()

    nbytes = shapeprod * itemsize

    if nbytes > size:
        raise ValueError(
                "Not enough bytes left in file for specified shape and type")

    # create the array
    _array = recarray(shape, descr)
    nbytesread = fd.readinto(_array.data)
    if nbytesread != nbytes:
        raise IOError("Didn't read as many bytes as expected")
    if name:
        fd.close()

    return _array
开发者ID:258073127,项目名称:MissionPlanner,代码行数:67,代码来源:records.py


示例15: fromrecords

def fromrecords(recList, dtype=None, shape=None, formats=None, names=None,
                titles=None, aligned=False, byteorder=None):
    """ create a recarray from a list of records in text form

        The data in the same field can be heterogeneous, they will be promoted
        to the highest data type.  This method is intended for creating
        smaller record arrays.  If used to create large array without formats
        defined

        r=fromrecords([(2,3.,'abc')]*100000)

        it can be slow.

        If formats is None, then this will auto-detect formats. Use list of
        tuples rather than list of lists for faster processing.

    >>> r=np.core.records.fromrecords([(456,'dbe',1.2),(2,'de',1.3)],
    ... names='col1,col2,col3')
    >>> print r[0]
    (456, 'dbe', 1.2)
    >>> r.col1
    array([456,   2])
    >>> r.col2
    chararray(['dbe', 'de'],
          dtype='|S3')
    >>> import cPickle
    >>> print cPickle.loads(cPickle.dumps(r))
    [(456, 'dbe', 1.2) (2, 'de', 1.3)]
    """

    nfields = len(recList[0])
    if formats is None and dtype is None:  # slower
        obj = sb.array(recList, dtype=object)
        arrlist = [sb.array(obj[..., i].tolist()) for i in xrange(nfields)]
        return fromarrays(arrlist, formats=formats, shape=shape, names=names,
                          titles=titles, aligned=aligned, byteorder=byteorder)

    if dtype is not None:
        descr = sb.dtype((record, dtype))
    else:
        descr = format_parser(formats, names, titles, aligned, byteorder)._descr

    try:
        retval = sb.array(recList, dtype=descr)
    except TypeError:  # list of lists instead of list of tuples
        if (shape is None or shape == 0):
            shape = len(recList)
        if isinstance(shape, (int, long)):
            shape = (shape,)
        if len(shape) > 1:
            raise ValueError, "Can only deal with 1-d array."
        _array = recarray(shape, descr)
        for k in xrange(_array.size):
            _array[k] = tuple(recList[k])
        return _array
    else:
        if shape is not None and retval.shape != shape:
            retval.shape = shape

    res = retval.view(recarray)

    return res
开发者ID:258073127,项目名称:MissionPlanner,代码行数:62,代码来源:records.py


示例16: fromarrays

def fromarrays(arrayList, dtype=None, shape=None, formats=None,
               names=None, titles=None, aligned=False, byteorder=None):
    """ create a record array from a (flat) list of arrays

    >>> x1=np.array([1,2,3,4])
    >>> x2=np.array(['a','dd','xyz','12'])
    >>> x3=np.array([1.1,2,3,4])
    >>> r = np.core.records.fromarrays([x1,x2,x3],names='a,b,c')
    >>> print r[1]
    (2, 'dd', 2.0)
    >>> x1[1]=34
    >>> r.a
    array([1, 2, 3, 4])
    """

    arrayList = [sb.asarray(x) for x in arrayList]

    if shape is None or shape == 0:
        shape = arrayList[0].shape

    if isinstance(shape, int):
        shape = (shape,)

    if formats is None and dtype is None:
        # go through each object in the list to see if it is an ndarray
        # and determine the formats.
        formats = ''
        for obj in arrayList:
            if not isinstance(obj, ndarray):
                raise ValueError, "item in the array list must be an ndarray."
            formats += _typestr[obj.dtype.type]
            if issubclass(obj.dtype.type, nt.flexible):
                formats += `obj.itemsize`
            formats += ','
        formats = formats[:-1]

    if dtype is not None:
        descr = sb.dtype(dtype)
        _names = descr.names
    else:
        parsed = format_parser(formats, names, titles, aligned, byteorder)
        _names = parsed._names
        descr = parsed._descr

    # Determine shape from data-type.
    if len(descr) != len(arrayList):
        raise ValueError, "mismatch between the number of fields "\
              "and the number of arrays"

    d0 = descr[0].shape
    nn = len(d0)
    if nn > 0:
        shape = shape[:-nn]

    for k, obj in enumerate(arrayList):
        nn = len(descr[k].shape)
        testshape = obj.shape[:len(obj.shape) - nn]
        if testshape != shape:
            raise ValueError, "array-shape mismatch in array %d" % k

    _array = recarray(shape, descr)

    # populate the record array (makes a copy)
    for i in range(len(arrayList)):
        _array[_names[i]] = arrayList[i]

    return _array
开发者ID:258073127,项目名称:MissionPlanner,代码行数:67,代码来源:records.py



注:本文中的numeric.dtype函数示例由纯净天空整理自Github/MSDocs等源码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。


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