import numpy as np
from ..boundingregion import BoundingBox
from ..dimension import Dimension
from ..element import Element
from ..ndmapping import NdMapping, item_check
from ..sheetcoords import Slice
from .. import util
from .grid import GridInterface
from .interface import Interface
[docs]class ImageInterface(GridInterface):
"""
Interface for 2 or 3D arrays representing images
of raw luminance values, RGB values or HSV values.
"""
types = (np.ndarray,)
datatype = 'image'
@classmethod
def init(cls, eltype, data, kdims, vdims):
if kdims is None:
kdims = eltype.kdims
if vdims is None:
vdims = eltype.vdims
kwargs = {}
dimensions = [d.name if isinstance(d, Dimension) else
d for d in kdims + vdims]
if isinstance(data, tuple):
data = dict(zip(dimensions, data))
if isinstance(data, dict):
xs, ys = np.asarray(data[kdims[0].name]), np.asarray(data[kdims[1].name])
l, r, xdensity, invertx = util.bound_range(xs, None, eltype._time_unit)
b, t, ydensity, inverty = util.bound_range(ys, None, eltype._time_unit)
kwargs['bounds'] = BoundingBox(points=((l, b), (r, t)))
if len(vdims) == 1:
data = np.flipud(np.asarray(data[vdims[0].name]))
else:
data = np.dstack([np.flipud(data[vd.name]) for vd in vdims])
if invertx:
data = data[:, ::-1]
if inverty:
data = data[::-1, :]
if not isinstance(data, np.ndarray) or data.ndim not in [2, 3]:
raise ValueError('ImageInterface expects a 2D array.')
return data, {'kdims':kdims, 'vdims':vdims}, kwargs
@classmethod
def shape(cls, dataset, gridded=False):
if gridded:
return dataset.data.shape
else:
return cls.length(dataset), len(dataset.dimensions())
@classmethod
def length(cls, dataset):
return np.product(dataset.data.shape)
@classmethod
def validate(cls, dataset, vdims=True):
pass
@classmethod
def redim(cls, dataset, dimensions):
return dataset.data
@classmethod
def reindex(cls, dataset, kdims=None, vdims=None):
data = dataset.data
dropped_kdims = [kd for kd in dataset.kdims if kd not in kdims]
constant = {}
for kd in dropped_kdims:
vals = cls.values(dataset, kd.name, expanded=False)
if len(vals) == 1:
constant[kd.name] = vals[0]
if dropped_kdims or constant:
return tuple(dataset.columns(kdims+vdims).values())
if vdims is not None and vdims != dataset.vdims and len(dataset.vdims) > 1:
inds = [dataset.get_dimension_index(vd)-dataset.ndims for vd in vdims]
return data[..., inds] if len(inds) > 1 else data[..., inds[0]]
return data
@classmethod
def coords(cls, dataset, dim, ordered=False, expanded=False):
dim = dataset.get_dimension(dim, strict=True)
if expanded:
return util.expand_grid_coords(dataset, dim)
return cls.values(dataset, dim, expanded=False)
@classmethod
def range(cls, obj, dim):
dim_idx = obj.get_dimension_index(dim)
if dim_idx in [0, 1] and obj.bounds:
l, b, r, t = obj.bounds.lbrt()
if dim_idx:
(low, high) = (b, t)
density = obj.ydensity
else:
low, high = (l, r)
density = obj.xdensity
halfd = (1./density)/2.
if isinstance(low, util.datetime_types):
halfd = np.timedelta64(int(round(halfd)), obj._time_unit)
drange = (low+halfd, high-halfd)
elif 1 < dim_idx < len(obj.vdims) + 2:
dim_idx -= 2
data = np.atleast_3d(obj.data)[:, :, dim_idx]
drange = (np.nanmin(data), np.nanmax(data))
else:
drange = (None, None)
return drange
[docs] @classmethod
def values(cls, dataset, dim, expanded=True, flat=True):
"""
The set of samples available along a particular dimension.
"""
dim_idx = dataset.get_dimension_index(dim)
if dim_idx in [0, 1]:
l, b, r, t = dataset.bounds.lbrt()
dim2, dim1 = dataset.data.shape[:2]
if isinstance(l, util.datetime_types):
xlin = util.date_range(l, r, dim1, dataset._time_unit)
else:
xstep = float(r - l)/dim1
xlin = np.linspace(l+(xstep/2.), r-(xstep/2.), dim1)
if isinstance(b, util.datetime_types):
ylin = util.date_range(b, t, dim2, dataset._time_unit)
else:
ystep = float(t - b)/dim2
ylin = np.linspace(b+(ystep/2.), t-(ystep/2.), dim2)
if expanded:
values = np.meshgrid(ylin, xlin)[abs(dim_idx-1)]
return values.flatten() if flat else values
else:
return ylin if dim_idx else xlin
elif dataset.ndims <= dim_idx < len(dataset.dimensions()):
# Raster arrays are stored with different orientation
# than expanded column format, reorient before expanding
if dataset.data.ndim > 2:
data = dataset.data[:, :, dim_idx-dataset.ndims]
else:
data = dataset.data
data = np.flipud(data)
return data.T.flatten() if flat else data
else:
return None
[docs] @classmethod
def select(cls, dataset, selection_mask=None, **selection):
"""
Slice the underlying numpy array in sheet coordinates.
"""
selection = {k: slice(*sel) if isinstance(sel, tuple) else sel
for k, sel in selection.items()}
coords = tuple(selection[kd.name] if kd.name in selection else slice(None)
for kd in dataset.kdims)
if not any([isinstance(el, slice) for el in coords]):
return dataset.data[dataset.sheet2matrixidx(*coords)]
# Apply slices
xidx, yidx = coords
l, b, r, t = dataset.bounds.lbrt()
if isinstance(xidx, slice):
l = l if xidx.start is None else max(l, xidx.start)
r = r if xidx.stop is None else min(r, xidx.stop)
if isinstance(yidx, slice):
b = b if yidx.start is None else max(b, yidx.start)
t = t if yidx.stop is None else min(t, yidx.stop)
bounds = BoundingBox(points=((l, b), (r, t)))
slc = Slice(bounds, dataset)
return slc.submatrix(dataset.data)
[docs] @classmethod
def sample(cls, dataset, samples=[]):
"""
Sample the Raster along one or both of its dimensions,
returning a reduced dimensionality type, which is either
a ItemTable, Curve or Scatter. If two dimension samples
and a new_xaxis is provided the sample will be the value
of the sampled unit indexed by the value in the new_xaxis
tuple.
"""
if len(samples[0]) == 1:
select = {dataset.kdims[0].name: [s[0] for s in samples]}
return tuple(dataset.select(**select).columns().values())
return [c+(dataset.data[dataset._coord2matrix(c)],) for c in samples]
@classmethod
def groupby(cls, dataset, dim_names, container_type, group_type, **kwargs):
# Get dimensions information
dimensions = [dataset.get_dimension(d) for d in dim_names]
kdims = [kdim for kdim in dataset.kdims if kdim not in dimensions]
# Update the kwargs appropriately for Element group types
group_kwargs = {}
group_type = dict if group_type == 'raw' else group_type
if issubclass(group_type, Element):
group_kwargs.update(util.get_param_values(dataset))
group_kwargs['kdims'] = kdims
group_kwargs.update(kwargs)
if len(dimensions) == 1:
didx = dataset.get_dimension_index(dimensions[0])
coords = dataset.dimension_values(dimensions[0], expanded=False)
xvals = dataset.dimension_values(abs(didx-1), expanded=False)
samples = [(i, slice(None)) if didx else (slice(None), i)
for i in range(dataset.data.shape[abs(didx-1)])]
data = np.flipud(dataset.data)
groups = [(c, group_type((xvals, data[s]), **group_kwargs))
for s, c in zip(samples, coords)]
else:
data = zip(*[dataset.dimension_values(i) for i in range(len(dataset.dimensions()))])
groups = [(g[:dataset.ndims], group_type([g[dataset.ndims:]], **group_kwargs))
for g in data]
if issubclass(container_type, NdMapping):
with item_check(False):
return container_type(groups, kdims=dimensions)
else:
return container_type(groups)
[docs] @classmethod
def unpack_scalar(cls, dataset, data):
"""
Given a dataset object and data in the appropriate format for
the interface, return a simple scalar.
"""
if np.isscalar(data) or len(data) != 1:
return data
key = list(data.keys())[0]
if len(data[key]) == 1 and key in dataset.vdims:
return data[key][0]
@classmethod
def aggregate(cls, dataset, kdims, function, **kwargs):
kdims = [kd.name if isinstance(kd, Dimension) else kd for kd in kdims]
axes = tuple(dataset.ndims-dataset.get_dimension_index(kdim)-1
for kdim in dataset.kdims if kdim not in kdims)
data = np.atleast_1d(function(dataset.data, axis=axes, **kwargs))
if not kdims:
if len(dataset.vdims) == 1:
return data if np.isscalar(data) else data[0]
else:
return {vd.name: np.array([v]) for vd, v in zip(dataset.vdims, data)}
elif len(axes) == 1:
return {kdims[0]: cls.values(dataset, axes[0], expanded=False),
dataset.vdims[0].name: data[::-1] if axes[0] else data}
Interface.register(ImageInterface)
