def delete_axis(block, axis):
"""Remove a unitary dimension from the frame
E.g., if the shape is [-1, 1, 3, 2], then
selecting axis=1 would change the shape to be
[-1, 3, 2].
Axis may be negative, or a string corresponding to an existing axis label.
"""
def header_transform(hdr, axis=axis):
tensor = hdr['_tensor']
specified_axis = axis
if isinstance(axis, str):
specified_axis = "'%s'" % specified_axis
axis = tensor['labels'].index(axis)
if axis < 0:
axis += len(tensor['shape']) + 1
if tensor['shape'][axis] != 1:
raise ValueError("Cannot delete non-unitary axis %s with shape %i"
% (specified_axis, tensor['shape'][axis]))
del tensor['shape'][axis]
if 'labels' in tensor:
del tensor['labels'][axis]
if 'scales' in tensor:
del tensor['scales'][axis]
if 'units' in tensor:
del tensor['units'][axis]
return hdr
return block_view(block, header_transform)
def rename_axis(block, old, new):
def header_transform(hdr, old=old, new=new):
axis = hdr['_tensor']['labels'].index(old)
hdr['_tensor']['labels'][axis] = new
return hdr
return block_view(block, header_transform)
def add_axis(block, axis, label=None, scale=None, units=None):
"""Add an extra dimension to the frame at position 'axis'
E.g., if the shape is [-1, 3, 2], then
selecting axis=1 would change the shape to be
[-1, 1, 3, 2].
Axis may be negative, or a string corresponding to an existing axis label,
in which case the new axis is inserted after the referenced axis.
"""
def header_transform(hdr, axis=axis, label=label, scale=scale, units=units):
tensor = hdr['_tensor']
if isinstance(axis, str):
axis = tensor['labels'].index(axis) + 1
if axis < 0:
axis += len(tensor['shape']) + 1
tensor['shape'].insert(axis, 1)
if 'labels' in tensor:
tensor['labels'].insert(axis, label)
if 'scales' in tensor:
tensor['scales'].insert(axis, scale)
if 'units' in tensor:
tensor['units'].insert(axis, units)
return hdr
return block_view(block, header_transform)
def split_axis(block, axis, n, label=None):
# Set function attributes to enable capture in nested function (closure)
def header_transform(hdr, axis=axis, n=n, label=label):
tensor = hdr['_tensor']
if isinstance(axis, str):
axis = tensor['labels'].index(axis)
shape = tensor['shape']
if shape[axis] == -1:
# Axis is frame axis
# TODO: Should assert even division here instead?
# ***TODO: Why does pipeline deadlock when this doesn't divide?
hdr['gulp_nframe'] = (hdr['gulp_nframe'] - 1) // n + 1
else:
# Axis is not frame axis
if shape[axis] % n:
raise ValueError("Split does not evenly divide axis (%i // %i)" %
(tensor['shape'][axis], n))
shape[axis] //= n
shape.insert(axis + 1, n)
if 'units' in tensor:
tensor['units'].insert(axis + 1, tensor['units'][axis])
if 'labels' in tensor:
if label is None:
label = tensor['labels'][axis] + "_split"
tensor['labels'].insert(axis + 1, label)
if 'scales' in tensor:
tensor['scales'].insert(axis + 1, [0, tensor['scales'][axis][1]])
tensor['scales'][axis][1] *= n
return hdr
return block_view(block, header_transform)
def reverse_scale(block, axis):
""" Manually reverse the scale factor on a given axis"""
def header_transform(hdr, axis=axis):
tensor = hdr['_tensor']
if isinstance(axis, str):
axis = tensor['labels'].index(axis)
tensor['scales'][axis][1] *= -1
return hdr
return block_view(block, header_transform)
def astype(block, dtype):
def header_transform(hdr, new_dtype=dtype):
tensor = hdr['_tensor']
old_dtype = tensor['dtype']
old_itemsize = DataType(old_dtype).itemsize
new_itemsize = DataType(new_dtype).itemsize
old_axissize = old_itemsize * tensor['shape'][-1]
if old_axissize % new_itemsize:
raise ValueError("New type not compatible with data shape")
tensor['shape'][-1] = old_axissize // new_itemsize
tensor['dtype'] = dtype
return hdr
return block_view(block, header_transform)
def reinterpret_axis(block, axis, label, scale=None, units=None):
""" Manually reinterpret the scale and/or units on an axis """
def header_transform(hdr, axis=axis, label=label, scale=scale, units=units):
tensor = hdr['_tensor']
if isinstance(axis, str):
axis = tensor['labels'].index(axis)
if label is not None:
tensor['labels'][axis] = label
if scale is not None:
tensor['scales'][axis] = scale
if units is not None:
tensor['units'][axis] = units
return hdr
return block_view(block, header_transform)
def merge_axes(block, axis1, axis2, label=None):
merge_axes.axis1 = axis1
merge_axes.axis2 = axis2
merge_axes.label = label
def header_transform(hdr):
axis1 = merge_axes.axis1
axis2 = merge_axes.axis2
label = merge_axes.label
tensor = hdr['_tensor']
if isinstance(axis1, basestring):
axis1 = tensor['labels'].index(axis1)
if isinstance(axis2, basestring):
axis2 = tensor['labels'].index(axis2)
axis1, axis2 = sorted([axis1, axis2])
if axis2 != axis1 + 1:
raise ValueError("Merge axes must be adjacent")
n = tensor['shape'][axis2]
if n == -1:
# Axis2 is frame axis
raise ValueError("Second merge axis cannot be frame axis")
elif tensor['shape'][axis1] == -1:
# Axis1 is frame axis
tensor['gulp_nframe'] *= n
else:
# Neither axis is frame axis
tensor['shape'][axis1] *= n
del tensor['shape'][axis2]
if 'scales' in tensor and 'units' in tensor:
scale1 = tensor['scales'][axis1][1]
scale2 = tensor['scales'][axis2][1]
units1 = tensor['units'][axis1]
units2 = tensor['units'][axis2]
scale2 = convert_units(scale2, units2, units1)
if not isclose(scale1, n * scale2):
raise ValueError("Scales of merge axes do not line up: "
"%f != %f" % (scale1, n * scale2))
tensor['scales'][axis1][1] = scale2
del tensor['scales'][axis2]
if 'labels' in tensor:
if label is not None:
tensor['labels'][axis1] = label
del tensor['labels'][axis2]
return hdr
return block_view(block, header_transform)
def expand_dims(block, axis, label, scale=None, units=None):
expand_dims.axis = axis
expand_dims.label = label
expand_dims.scale = scale
expand_dims.units = units
def header_transform(hdr):
axis = expand_dims.axis
label = expand_dims.label
scale = expand_dims.scale
units = expand_dims.units
tensor = hdr['tensor']
if isinstance(axis, basestring):
axis = tensor['labels'].index(axis)
tensor['shape'].insert(axis, 1)
tensor['labels'].insert(axis, label)
tensor['scales'].insert(axis, scale)
tensor['units'].insert(axis, units)
return hdr
return block_view(block, header_transform)
def expand_dims(block, axis, label, scale=None, units=None):
"""Add an extra dimension to the frame
As in, if the shape is [-1, 3, 2], then
selecting axis=1 would change the shape to be
[-1, 3, 1, 2].
"""
def header_transform(hdr,
axis=axis,
label=label,
scale=scale,
units=units):
tensor = hdr['tensor']
if isinstance(axis, basestring):
axis = tensor['labels'].index(axis)
tensor['shape'].insert(axis, 1)
tensor['labels'].insert(axis, label)
tensor['scales'].insert(axis, scale)
tensor['units'].insert(axis, units)
return hdr
return block_view(block, header_transform)
def custom(block, hdr_transform):
"""An alias to `bifrost.pipeline.block_view`
"""
return block_view(block, hdr_transform)
def custom(block, hdr_transform):
return block_view(block, header_transform)
