How Do I...?¶
Note
This section is currently under active development.
Basics¶
How do I...
- render data to an image file?
def save_plot(plot, filename, width, height):
plot.outer_bounds = [width, height]
plot.do_layout(force=True)
gc = PlotGraphicsContext((width, height), dpi=72)
gc.render_component(plot)
gc.save(filename)
- integrate a Chaco plot into my WX app?
import wx
from numpy import arange
from scipy.special import jn
from chaco.api import HPlotContainer, create_line_plot
from enable.api import Window
class PlotFrame(wx.Frame):
def __init__(self, *args, **kw):
kw["size"] = (850, 550)
wx.Frame.__init__( *(self,) + args, **kw )
self.plot_window = Window(self, component=self._create_plot())
sizer = wx.BoxSizer(wx.HORIZONTAL)
sizer.Add(self.plot_window.control, 1, wx.EXPAND)
self.SetSizer(sizer)
self.SetAutoLayout(True)
self.Show(True)
return
def _create_plot(self):
x = arange(-5.0, 15.0, 20.0/100)
y = jn(0, x)
plot = create_line_plot((x,y), bgcolor="white",
add_grid=True, add_axis=True)
container = HPlotContainer(spacing=20, padding=50, bgcolor="lightgray")
container.add(plot)
return container
if __name__ == "__main__":
app = wx.PySimpleApp()
frame = PlotFrame(None)
app.MainLoop()
Note that this will require for the ETS_TOOLKIT environment variable to be set to ‘wx’.
- integrate a Chaco plot into my QT app?
- integrate a Chaco plot into my Traits UI?
import numpy
from chaco.api import Plot, ArrayPlotData
from enable.component_editor import ComponentEditor
from traits.api import HasTraits, Instance
from traitsui.api import Item, View
class MyPlot(HasTraits):
plot = Instance(Plot)
traits_view = View(Item('plot', editor=ComponentEditor()))
def __init__(self, index, data_series, **kw):
super(MyPlot, self).__init__(**kw)
plot_data = ArrayPlotData(index=index)
plot_data.set_data('data_series', data_series)
self.plot = Plot(plot_data)
self.plot.plot(('index', 'data_series'))
index = numpy.array([1,2,3,4,5])
data_series = index**2
my_plot = MyPlot(index, data_series)
my_plot.configure_traits()
- make an application to render many streams of data?
def plot_several_series(index, series_list):
plot_data = ArrayPlotData(index=index)
plot = Plot(plot_data)
for i, data_series in enumerate(series_list):
series_name = "series_%d" % i
plot_data.set_data(series_name, data_series)
plot.plot(('index', series_name))
- make a plot the right size?
def resize_plot(plot, width, height):
plot.outer_bounds = [width, height]
- copy a plot the the clipboard?
def copy_to_clipboard(plot):
# WX specific, though QT implementation is similar using
# QImage and QClipboard
import wx
width, height = plot.outer_bounds
gc = PlotGraphicsContext((width, height), dpi=72)
gc.render_component(plot_component)
# Create a bitmap the same size as the plot
# and copy the plot data to it
bitmap = wx.BitmapFromBufferRGBA(width+1, height+1,
gc.bmp_array.flatten())
data = wx.BitmapDataObject()
data.SetBitmap(bitmap)
if wx.TheClipboard.Open():
wx.TheClipboard.SetData(data)
wx.TheClipboard.Close()
else:
wx.MessageBox("Unable to open the clipboard.", "Error")
Layout and Rendering¶
How do I...
- put multiple plots in a single window?
- change the background color?
def make_black_plot(index, data_series):
plot_data = ArrayPlotData(index=index)
plot_data.set_data('data_series', data_series)
plot = Plot(plot_data, bgcolor='black')
plot.plot(('index', 'data_series'))
def change_bgcolor(plot):
plot.bgcolor = 'black'
- turn off borders?
def make_borderless_plot(index, data_series):
plot_data = ArrayPlotData(index=index)
plot_data.set_data('data_series', data_series)
plot = Plot(plot_data, border_visible=False)
plot.plot(('index', 'data_series'))
def change_to_borderless_plot(plot):
plot.border_visible = False
Writing Components¶
How do I...
- compose multiple renderers?
- write a custom renderer?
- write a custom overlay/underlay?
- write a custom tool?
- write a new container?
Advanced¶
How do I...
- properly change/override draw dispatch?
- modify event dispatch?
- customize backbuffering?
- embed custom/native WX widgets on the plot?