def setshape(self, shape, *args):
"""Change array shape in place. Call as setshape(i,j,k) or setshape((i,j,k))."""
if not self.iscontiguous():
raise ValueError("Can't reshape non-contiguous numarray")
shape = list(getShape(shape, *args))
# look for index = -1, which indicates an expandable dimension
nelements = self.nelements()
negcount = shape.count(-1)
if negcount > 1:
raise ValueError("no more than one dimension can have value -1")
elif negcount == 1:
tnelements = abs(product(shape))
shape[shape.index(-1)] = nelements/tnelements
newnelements = product(shape)
if newnelements == nelements:
self._shape = tuple(shape)
self._strides = self._stridesFromShape()
else:
raise ValueError("New shape is not consistent with the old shape")
def copy(self):
"""Return a new array with the same shape and type, but a copy of the data"""
arr = self.view()
arr._data = memory.new_memory(arr._itemsize * arr.nelements())
arr._byteoffset = 0
arr._bytestride = arr._itemsize
arr._strides = arr._stridesFromShape()
arr._itemsize = self._itemsize
# now copy data, if possible using larger units
if product(self._shape):
fname = "copy"+str(self._itemsize)+"bytes"
copyfunction = ((self.isaligned() and
_bytes.functionDict.get(fname))
or _bytes.functionDict["copyNbytes"])
copyfunction(arr._shape, self._data, self._byteoffset,
self._strides, arr._data, 0, arr._strides,
arr._itemsize)
return arr
def resize(self, shape, *args):
""" resize() shrinks/grows 'self' to new 'shape', possibly
replacing the underlying buffer object.
"""
shape = getShape(shape, *args)
nlen = product(shape)
if nlen < 0:
raise ValueError("Negative shape dims don't work with resize")
olen = self.nelements()
if (isinstance(self._data, _types.BufferType) or
isinstance(self._data, memory.MemoryType)):
if self.iscontiguous():
oself = self.view()
else:
oself = self.copy()
self._data = memory.new_memory(nlen*self._itemsize)
self._bytestride = self._itemsize
self._byteoffset = 0
blen = min(nlen, olen)
self.ravel()
oself.ravel()
self[:blen] = oself[:blen]
else: # Memmap
self._data.resize(nlen*self._itemsize)
self._shape = (nlen,)
self._strides = self._stridesFromShape()
if olen: # use any existing data as a pattern to be repeated
if nlen > olen:
offset = olen
while offset+olen <= nlen:
self[offset:offset+olen] = self[0:olen]
offset += olen
self[offset:nlen] = self[0:nlen-offset]
else: # zero fill resized zero-length numarray
self[:] = 0
self._shape = shape
self._strides = self._stridesFromShape()
return self