iris_splom.py¶

from __future__ import print_function

from bokeh.document import Document
from bokeh.embed import file_html
from bokeh.layouts import gridplot
from bokeh.models.glyphs import Circle
from bokeh.models import (BasicTicker, ColumnDataSource, Grid, LinearAxis,
                         DataRange1d, PanTool, Plot, WheelZoomTool)
from bokeh.resources import INLINE
from bokeh.sampledata.iris import flowers
from bokeh.util.browser import view

colormap = {'setosa': 'red', 'versicolor': 'green', 'virginica': 'blue'}

flowers['color'] = flowers['species'].map(lambda x: colormap[x])


source = ColumnDataSource(
    data=dict(
        petal_length=flowers['petal_length'],
        petal_width=flowers['petal_width'],
        sepal_length=flowers['sepal_length'],
        sepal_width=flowers['sepal_width'],
        color=flowers['color']
    )
)

xdr = DataRange1d(bounds=None)
ydr = DataRange1d(bounds=None)

def make_plot(xname, yname, xax=False, yax=False):
    mbl = 40 if yax else 0
    mbb = 40 if xax else 0
    plot = Plot(
        x_range=xdr, y_range=ydr, background_fill_color="#efe8e2",
        border_fill_color='white', plot_width=200 + mbl, plot_height=200 + mbb,
        min_border_left=2+mbl, min_border_right=2, min_border_top=2, min_border_bottom=2+mbb)

    circle = Circle(x=xname, y=yname, fill_color="color", fill_alpha=0.2, size=4, line_color="color")
    r = plot.add_glyph(source, circle)

    xdr.renderers.append(r)
    ydr.renderers.append(r)

    xticker = BasicTicker()
    if xax:
        xaxis = LinearAxis()
        plot.add_layout(xaxis, 'below')
        xticker = xaxis.ticker
    plot.add_layout(Grid(dimension=0, ticker=xticker))

    yticker = BasicTicker()
    if yax:
        yaxis = LinearAxis()
        plot.add_layout(yaxis, 'left')
        yticker = yaxis.ticker
    plot.add_layout(Grid(dimension=1, ticker=yticker))

    plot.add_tools(PanTool(), WheelZoomTool())

    return plot

xattrs = ["petal_length", "petal_width", "sepal_width", "sepal_length"]
yattrs = list(reversed(xattrs))
plots = []

for y in yattrs:
    row = []
    for x in xattrs:
        xax = (y == yattrs[-1])
        yax = (x == xattrs[0])
        plot = make_plot(x, y, xax, yax)
        row.append(plot)
    plots.append(row)

grid = gridplot(plots)

doc = Document()
doc.add_root(grid)

if __name__ == "__main__":
    doc.validate()
    filename = "iris_splom.html"
    with open(filename, "w") as f:
        f.write(file_html(doc, INLINE, "Iris Data SPLOM"))
    print("Wrote %s" % filename)
    view(filename)