Source code for holoviews.plotting.mpl.raster

import numpy as np
import param

from ...core import CompositeOverlay, Element
from ...core import traversal
from ...core.util import match_spec, max_range, unique_iterator
from ...element.raster import Image, Raster, RGB
from .element import ColorbarPlot, OverlayPlot
from .plot import MPLPlot, GridPlot, mpl_rc_context
from .util import get_raster_array

class RasterPlot(ColorbarPlot):

    aspect = param.Parameter(default='equal', doc="""
        Raster elements respect the aspect ratio of the
        Images by default but may be set to an explicit
        aspect ratio or to 'square'.""")

    clipping_colors = param.Dict(default={'NaN': 'transparent'})

    colorbar = param.Boolean(default=False, doc="""
        Whether to add a colorbar to the plot.""")

    show_legend = param.Boolean(default=False, doc="""
        Whether to show legend for the plot.""")

    situate_axes = param.Boolean(default=True, doc="""
        Whether to situate the image relative to other plots. """)

    style_opts = ['alpha', 'cmap', 'interpolation', 'visible',
                  'filterrad', 'clims', 'norm']

    _plot_methods = dict(single='imshow')

    def __init__(self, *args, **kwargs):
        super(RasterPlot, self).__init__(*args, **kwargs)
        if self.hmap.type == Raster:
            self.invert_yaxis = not self.invert_yaxis

    def get_extents(self, element, ranges):
        extents = super(RasterPlot, self).get_extents(element, ranges)
        if self.situate_axes:
            return extents
            if isinstance(element, Image):
                return element.bounds.lbrt()
                return element.extents

    def _compute_ticks(self, element, ranges):
        return None, None

    def get_data(self, element, ranges, style):
        xticks, yticks = self._compute_ticks(element, ranges)

        if isinstance(element, RGB):
            style.pop('cmap', None)

        data = get_raster_array(element)
        if type(element) is Raster:
            l, b, r, t = element.extents
            if self.invert_axes:
                data = data[:, ::-1]
                data = data[::-1]
            l, b, r, t = element.bounds.lbrt()
            if self.invert_axes:
                data = data[::-1, ::-1]

        if self.invert_axes:
            data = data.transpose([1, 0, 2]) if isinstance(element, RGB) else data.T
            l, b, r, t = b, l, t, r

        vdim = element.vdims[0]
        self._norm_kwargs(element, ranges, style, vdim)
        style['extent'] = [l, r, b, t]
        style['origin'] = 'upper'

        return [data], style, {'xticks': xticks, 'yticks': yticks}

    def update_handles(self, key, axis, element, ranges, style):
        im = self.handles['artist']
        data, style, axis_kwargs = self.get_data(element, ranges, style)
        l, r, b, t = style['extent']
        im.set_extent((l, r, b, t))
        im.set_clim((style['vmin'], style['vmax']))
        if 'norm' in style:
            im.norm = style['norm']

        return axis_kwargs

class QuadMeshPlot(ColorbarPlot):

    clipping_colors = param.Dict(default={'NaN': 'transparent'})

    show_legend = param.Boolean(default=False, doc="""
        Whether to show legend for the plot.""")

    style_opts = ['alpha', 'cmap', 'clims', 'edgecolors', 'norm', 'shading',
                  'linestyles', 'linewidths', 'hatch', 'visible']

    _plot_methods = dict(single='pcolormesh')

    def get_data(self, element, ranges, style):
        zdata = element.dimension_values(2, flat=False)
        data =, mask=np.logical_not(np.isfinite(zdata)))
        expanded = element.interface.irregular(element, element.kdims[0])
        edges = style.get('shading') != 'gouraud'
        coords = [element.interface.coords(element, d, ordered=True,
                                           expanded=expanded, edges=edges)
                  for d in element.kdims]
        if self.invert_axes:
            coords = coords[::-1]
            data = data.T
        cmesh_data = coords + [data]
        if expanded:
            style['locs'] = np.concatenate(coords)
        vdim = element.vdims[0]
        self._norm_kwargs(element, ranges, style, vdim)
        return tuple(cmesh_data), style, {}

    def init_artists(self, ax, plot_args, plot_kwargs):
        locs = plot_kwargs.pop('locs', None)
        artist = ax.pcolormesh(*plot_args, **plot_kwargs)
        colorbar = self.handles.get('cbar')
        if colorbar:
        return {'artist': artist, 'locs': locs}

[docs]class RasterGridPlot(GridPlot, OverlayPlot): """ RasterGridPlot evenly spaces out plots of individual projections on a grid, even when they differ in size. Since this class uses a single axis to generate all the individual plots it is much faster than the equivalent using subplots. """ # Parameters inherited from OverlayPlot that are not part of the # GridPlot interface. Some of these may be enabled in future in # conjunction with GridPlot. apply_extents = param.Parameter(precedence=-1) apply_ranges = param.Parameter(precedence=-1) apply_ticks = param.Parameter(precedence=-1) batched = param.Parameter(precedence=-1) bgcolor = param.Parameter(precedence=-1) invert_axes = param.Parameter(precedence=-1) invert_xaxis = param.Parameter(precedence=-1) invert_yaxis = param.Parameter(precedence=-1) invert_zaxis = param.Parameter(precedence=-1) labelled = param.Parameter(precedence=-1) legend_cols = param.Parameter(precedence=-1) legend_position = param.Parameter(precedence=-1) legend_limit = param.Parameter(precedence=-1) logx = param.Parameter(precedence=-1) logy = param.Parameter(precedence=-1) logz = param.Parameter(precedence=-1) show_grid = param.Parameter(precedence=-1) style_grouping = param.Parameter(precedence=-1) xticks = param.Parameter(precedence=-1) yticks = param.Parameter(precedence=-1) zticks = param.Parameter(precedence=-1) zaxis = param.Parameter(precedence=-1) zrotation = param.Parameter(precedence=-1) def __init__(self, layout, keys=None, dimensions=None, create_axes=False, ranges=None, layout_num=1, **params): top_level = keys is None if top_level: dimensions, keys = traversal.unique_dimkeys(layout) MPLPlot.__init__(self, dimensions=dimensions, keys=keys, **params) if top_level: self.comm = self.init_comm() self.layout = layout self.cyclic_index = 0 self.zorder = 0 self.layout_num = layout_num self.overlaid = False self.hmap = layout if layout.ndims > 1: xkeys, ykeys = zip(* else: xkeys = layout.keys() ykeys = [None] self._xkeys = sorted(set(xkeys)) self._ykeys = sorted(set(ykeys)) self._xticks, self._yticks = [], [] self.rows, self.cols = layout.shape self.fig_inches = self._get_size() _, _, self.layout = self._create_subplots(layout, None, ranges, create_axes=False) self.border_extents = self._compute_borders() width, height, _, _, _, _ = self.border_extents if self.aspect == 'equal': self.aspect = float(width/height) # Note that streams are not supported on RasterGridPlot # until that is implemented this stub is needed self.streams = [] def _finalize_artist(self, key): pass def get_extents(self, view, ranges): width, height, _, _, _, _ = self.border_extents return (0, 0, width, height) def _get_frame(self, key): return GridPlot._get_frame(self, key) @mpl_rc_context def initialize_plot(self, ranges=None): _, _, b_w, b_h, widths, heights = self.border_extents key = self.keys[-1] ranges = self.compute_ranges(self.layout, key, ranges) self.handles['projs'] = {} x, y = b_w, b_h for xidx, xkey in enumerate(self._xkeys): w = widths[xidx] for yidx, ykey in enumerate(self._ykeys): h = heights[yidx] if self.layout.ndims > 1: vmap = self.layout.get((xkey, ykey), None) else: vmap = self.layout.get(xkey, None) pane =**{ val for d, val in zip(self.dimensions, key) if d in vmap.kdims}) pane = vmap.last.values()[-1] if issubclass(vmap.type, CompositeOverlay) else vmap.last data = get_raster_array(pane) if pane else None ranges = self.compute_ranges(vmap, key, ranges) opts = self.lookup_options(pane, 'style')[self.cyclic_index] plot = self.handles['axis'].imshow(data, extent=(x,x+w, y, y+h), **opts) cdim = pane.vdims[0].name valrange = match_spec(pane, ranges).get(cdim, pane.range(cdim)) plot.set_clim(valrange) if data is None: plot.set_visible(False) self.handles['projs'][(xkey, ykey)] = plot y += h + b_h if xidx == 0: self._yticks.append(y-b_h-h/2.) y = b_h x += w + b_w self._xticks.append(x-b_w-w/2.) kwargs = self._get_axis_kwargs() return self._finalize_axis(key, ranges=ranges, **kwargs) @mpl_rc_context def update_frame(self, key, ranges=None): grid = self._get_frame(key) ranges = self.compute_ranges(self.layout, key, ranges) for xkey in self._xkeys: for ykey in self._ykeys: plot = self.handles['projs'][(xkey, ykey)] grid_key = (xkey, ykey) if self.layout.ndims > 1 else (xkey,) element =, None) if element: plot.set_visible(True) img = element.values()[0] if isinstance(element, CompositeOverlay) else element data = get_raster_array(img) plot.set_data(data) else: plot.set_visible(False) kwargs = self._get_axis_kwargs() return self._finalize_axis(key, ranges=ranges, **kwargs) def _get_axis_kwargs(self): xdim = self.layout.kdims[0] ydim = self.layout.kdims[1] if self.layout.ndims > 1 else None xticks = (self._xticks, [xdim.pprint_value(l) for l in self._xkeys]) yticks = (self._yticks, [ydim.pprint_value(l) if ydim else '' for l in self._ykeys]) return dict(xlabel=xdim.pprint_label, ylabel=ydim.pprint_label if ydim else '', xticks=xticks, yticks=yticks) def _compute_borders(self): ndims = self.layout.ndims width_fn = lambda x: x.range(0) height_fn = lambda x: x.range(1) width_extents = [max_range(self.layout[x, :].traverse(width_fn, [Element])) for x in unique_iterator(self.layout.dimension_values(0))] if ndims > 1: height_extents = [max_range(self.layout[:, y].traverse(height_fn, [Element])) for y in unique_iterator(self.layout.dimension_values(1))] else: height_extents = [max_range(self.layout.traverse(height_fn, [Element]))] widths = [extent[0]-extent[1] for extent in width_extents] heights = [extent[0]-extent[1] for extent in height_extents] width, height = np.sum(widths), np.sum(heights) border_width = (width*self.padding)/(len(widths)+1) border_height = (height*self.padding)/(len(heights)+1) width += width*self.padding height += height*self.padding return width, height, border_width, border_height, widths, heights def __len__(self): return max([len(self.keys), 1])