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Implementation of a plut using a custom overlay and tool
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from __future__ import with_statement
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from enthought.traits.api import HasTraits, Instance, Enum
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from enthought.traits.ui.api import View, Item
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from enthought.enable.api import ComponentEditor
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from enthought.chaco.api import Plot, ArrayPlotData, AbstractOverlay
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from enthought.enable.api import BaseTool
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from enthought.enable.markers import DOT_MARKER, DotMarker
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class BoxSelectTool(BaseTool):
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""" Tool for selecting all points within a box
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There are 2 states for this tool, normal and selecting. While the
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left mouse button is down the metadata on the datasources will be
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updated with the current selected bounds.
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Note that the tool does not actually store the selected point, but the
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event_state = Enum("normal", "selecting")
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def normal_left_down(self, event):
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self.event_state = "selecting"
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self.selecting_mouse_move(event)
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def selecting_left_up(self, event):
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self.event_state = "normal"
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def selecting_mouse_move(self, event):
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x1, y1 = self.map_to_data(event.x-25, event.y-25)
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x2, y2 = self.map_to_data(event.x+25, event.y+25)
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index_datasource = self.component.index
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index_datasource.metadata['selections'] = (x1, x2)
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value_datasource = self.component.value
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value_datasource.metadata['selections'] = (y1, y2)
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self.component.request_redraw()
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def map_to_data(self, x, y):
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""" Returns the data space coordinates of the given x and y.
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Takes into account orientation of the plot and the axis setting.
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if plot.orientation == "h":
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index = plot.x_mapper.map_data(x)
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value = plot.y_mapper.map_data(y)
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index = plot.y_mapper.map_data(y)
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value = plot.x_mapper.map_data(x)
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class XRayOverlay(AbstractOverlay):
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""" Overlay which draws scatter markers on top of plot data points.
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This overlay should be combined with a tool which updates the
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datasources metadata with selection bounds.
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def overlay(self, component, gc, view_bounds=None, mode='normal'):
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x_range = self._get_selection_index_screen_range()
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y_range = self._get_selection_value_screen_range()
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gc.set_fill_color((1.0,1.0,1.0))
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gc.rect(x1, y1, x2-x1, y2-y1)
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pts = self._get_selected_points()
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screen_pts = self.component.map_screen(pts)
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if hasattr(gc, 'draw_marker_at_points'):
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gc.draw_marker_at_points(screen_pts, 3, DOT_MARKER)
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for sx,sy in screen_pts:
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gc.translate_ctm(sx, sy)
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self.marker.add_to_path(gc, 3)
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gc.draw_path(self.marker.draw_mode)
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gc.translate_ctm(-sx, -sy)
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def _get_selected_points(self):
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""" gets all the points within the bounds defined in the datasources
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index_datasource = self.component.index
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index_selection = index_datasource.metadata['selections']
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index = index_datasource.get_data()
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value_datasource = self.component.value
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value_selection = value_datasource.metadata['selections']
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value = value_datasource.get_data()
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x_indices = numpy.where((index > index_selection[0]) & (index < index_selection[-1]))
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y_indices = numpy.where((value > value_selection[0]) & (value < value_selection[-1]))
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indices = list(set(x_indices[0]) & set(y_indices[0]))
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sel_index = index[indices]
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sel_value = value[indices]
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return zip(sel_index, sel_value)
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def _get_selection_index_screen_range(self):
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""" maps the selected bounds which were set by the tool into screen
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space. The screen space points can be used for drawing the overlay
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index_datasource = self.component.index
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index_mapper = self.component.index_mapper
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index_selection = index_datasource.metadata['selections']
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return tuple(index_mapper.map_screen(numpy.array(index_selection)))
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def _get_selection_value_screen_range(self):
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""" maps the selected bounds which were set by the tool into screen
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space. The screen space points can be used for drawing the overlay
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value_datasource = self.component.value
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value_mapper = self.component.value_mapper
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value_selection = value_datasource.metadata['selections']
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return tuple(value_mapper.map_screen(numpy.array(value_selection)))
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class PlotExample(HasTraits):
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plot = Instance(Plot)
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traits_view = View(Item('plot', editor=ComponentEditor()),
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width=600, height=600)
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def __init__(self, index, value, *args, **kw):
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super(PlotExample, self).__init__(*args, **kw)
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plot_data = ArrayPlotData(index=index)
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plot_data.set_data('value', value)
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self.plot = Plot(plot_data)
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line = self.plot.plot(('index', 'value'))[0]
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line.overlays.append(XRayOverlay(line))
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line.tools.append(BoxSelectTool(line))
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index = numpy.arange(0, 25, 0.25)
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value = numpy.sin(index) + numpy.arange(0, 10, 0.1)
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example = PlotExample(index, value)
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example.configure_traits()
added
removed
examples/xray_plot.py
