Chaco 堆叠条 plot 每个条和段都有不同的颜色

Question

我试图在 Chaco 堆叠条 plot 中控制每个条和每个条段的颜色。

例如，运行 Chaco 的堆叠条 plot 示例给出，

我怎么把它变成这个怪物？

我可以看到 Chaco 有ColourMapped Scatter Plot可以控制每个点。 我需要这种行为，但需要条形图。 有没有一种快速的方法来做到这一点？

这是演示。 生成默认 Chaco Stacked Bar 的代码 Plot

"""
Simple example of a stacked bar chart
"""

# Major library imports
import numpy

# Enthought library imports
from enable.api import ComponentEditor
from traits.api import HasTraits, Instance
from traitsui.api import UItem, View

# Chaco imports
from chaco.api import LabelAxis, Plot, ArrayPlotData, ArrayDataSource


class PlotExample(HasTraits):

    plot = Instance(Plot)

    def _plot_default(self):
        index = numpy.array([1, 2, 3, 4, 5])
        series_a, series_b, series_c = (index * 10, index * 5, index * 2)
        # Stack them up
        series_c = series_c + series_b + series_a
        series_b = series_b + series_a

        plot_data = ArrayPlotData(index=index)
        plot_data.set_data("series_a", series_a)
        plot_data.set_data("series_b", series_b)
        plot_data.set_data("series_c", series_c)
        plot = Plot(plot_data)
        plot.plot(("index", "series_a"), type="bar", bar_width=0.8, color="auto")
        plot.plot(
            ("index", "series_b"),
            type="bar",
            bar_width=0.8,
            color="auto",
            starting_value=ArrayDataSource(series_a),
        )
        plot.plot(
            ("index", "series_c"),
            type="bar",
            bar_width=0.8,
            color="auto",
            starting_value=ArrayDataSource(series_b),
        )

        # set the plot's value range to 0, otherwise it may pad too much
        plot.value_range.low = 0

        # replace the index values with some nicer labels
        label_axis = LabelAxis(
            plot,
            orientation="bottom",
            title="Months",
            positions=list(range(1, 10)),
            labels=["jan", "feb", "march", "april", "may"],
            small_haxis_style=True,
        )

        plot.underlays.remove(plot.index_axis)
        plot.index_axis = label_axis
        plot.underlays.append(label_axis)

        return plot

    traits_view = View(
        UItem("plot", editor=ComponentEditor()), width=400, height=400, resizable=True,
    )


demo = PlotExample()

if __name__ == "__main__":
    demo.configure_traits()

Answer 1

我将通过为堆叠条形图中的每个段制作一个单独的条形 plot 渲染器来解决这个问题。 像这样的东西应该可以解决问题（对于非常冗长for语句感到抱歉）：

"""
Simple example of a stacked bar chart
"""

# Major library imports
import numpy

# Enthought library imports
from enable.api import ComponentEditor
from traits.api import HasTraits, Instance
from traitsui.api import UItem, View

# Chaco imports
from chaco.api import LabelAxis, Plot, ArrayPlotData, ArrayDataSource


class PlotExample(HasTraits):

    plot = Instance(Plot)

    def _plot_default(self):
        index = numpy.array([1, 2, 3, 4, 5])
        series_a, series_b, series_c = (index * 10, index * 5, index * 2)
        # Stack them up
        series_c = series_c + series_b + series_a
        series_b = series_b + series_a

        plot_data = ArrayPlotData()
        for i, (index_val, series_a_val, series_b_val, series_c_val) in enumerate(zip(
            index, series_a, series_b, series_c
        )):
            plot_data.set_data(f"index_{i}", [index_val])
            plot_data.set_data(f"series_a_{i}", [series_a_val])
            plot_data.set_data(f"series_b_{i}", [series_b_val])
            plot_data.set_data(f"series_c_{i}", [series_c_val])

        plot = Plot(plot_data)

        for i, (index_val, series_a_val, series_b_val, series_c_val) in enumerate(zip(
            index, series_a, series_b, series_c
        )):
            plot.plot(
                (f"index_{i}", f"series_a_{i}"),
                type="bar",
                bar_width=0.8,
                color="auto",
            )
            plot.plot(
                (f"index_{i}", f"series_b_{i}"),
                type="bar",
                bar_width=0.8,
                color="auto",
                starting_value=ArrayDataSource([series_a_val]),
            )
            plot.plot(
                (f"index_{i}", f"series_c_{i}"),
                type="bar",
                bar_width=0.8,
                color="auto",
                starting_value=ArrayDataSource([series_b_val]),
            )

        # set the plot's value range to 0, otherwise it may pad too much
        plot.value_range.low = 0

        # replace the index values with some nicer labels
        label_axis = LabelAxis(
            plot,
            orientation="bottom",
            title="Months",
            positions=list(range(1, 10)),
            labels=["jan", "feb", "march", "april", "may"],
            small_haxis_style=True,
        )

        plot.underlays.remove(plot.index_axis)
        plot.index_axis = label_axis
        plot.underlays.append(label_axis)

        return plot

    traits_view = View(
        UItem("plot", editor=ComponentEditor()), width=400, height=400, resizable=True,
    )


demo = PlotExample()

if __name__ == "__main__":
    demo.configure_traits()

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