def __init__(self, master, gradient_table, width, height ):
        tk.Frame.__init__(self, master, borderwidth=2, relief='groove')
        self.width = width
        self.height = height
        self.gradient_table = gradient_table
        assert( gradient_table.size == width )
        # ^- currently only able to use gradient tables in the same
        # size as the canvas width
        self.canvas = tk.Canvas(self, background="white", width=width,
                height=height)
        self.canvas.pack()
        self.update()
master: frame in which to place the control. GradientTable is the
dataset/ETHPy150Open enthought/mayavi/tvtk/util/tk_gradient_editor.py/GradientControl.__init__