chaco.plots.colormapped_scatterplot module¶
Defines the ColormappedScatterPlot and ColormappedScatterPlotView classes.
-
class
chaco.plots.colormapped_scatterplot.
ColormappedScatterPlot
(**kwtraits)¶ Bases:
chaco.plots.scatterplot.ScatterPlot
A scatter plot that allows each point to take on a different color, corresponding to a color map.
If the color_data or color_mapper attributes are None, then it behaves like a normal ScatterPlot.
-
color_data
= Instance(ArrayDataSource)¶ Source for color data.
-
color_mapper
= Instance(AbstractColormap)¶ Mapping for colors.
-
fill_alpha
= Float(1.0)¶ The alpha value to apply to the result of the color-mapping process. (This makes it easier to create color maps without having to worry about alpha.)
-
map_screen
(data_array)¶ Maps an array of data points into screen space, and returns them as an array.
The data_array parameter must be an Nx2 (index, value) or Nx3 (index, value, color_value) array. The returned array is an Nx2 array of (x, y) tuples.
-
render_method
= Enum("auto", "banded", "bruteforce")¶ Determines what drawing approach to use:
- banded:
Draw the points color-band by color-band, thus reducing the number of set_stroke_color() calls. Disadvantage is that some colors will appear more prominently than others if there are a lot of overlapping points.
- bruteforce:
Set the stroke color before drawing each marker. Slower, but doesn’t produce the banding effect that puts some colors on top of others; useful if there is a lot of overlap of the data.
- auto:
Determines which render method to use based on the number of points
TODO: Based on preliminary results, “banded” isn’t significantly more expensive than “bruteforce” for small datasets (<1000), so perhaps banded should be removed.
-
traits_view
¶ TraitsUI View for customizing the plot. Overrides the ScatterPlot value.
-
-
class
chaco.plots.colormapped_scatterplot.
ColormappedScatterPlotView
¶ Bases:
chaco.plots.scatterplot.ScatterPlotView
TraitsUI View for customizing a color-mapped scatter plot.