5. Utilities

5.1. GUI Application Helper

TkBuilder GUI Application with a window title and the default witkets style.

One typical usage is to inherit the Application class and implement solution-specific methods.

A minimalist example without inheritance is given below:

>>> import witkets as wtk
>>> app = wtk.Application(ui_filename='demo.xml', title='Demo')
>>> mainwindow = app.root # tk.Tk instance
>>> builder = app.builder # TkBuilder instance
>>> app.run()             # call app.root.mainloop()

class witkets.application.Application(ui_filename=None, title=None, theme=None, **kw)

A GUI Application.

Parameters

ui_filename (str) – path to the XML used by TkBuilder

Keyword Arguments

• title (str) – window title

• theme (str) – theme name

• kw (dict) – Any of the tk.Tk keyword arguments

run()

Enter the application event loop.

5.2. Coordinate Normalization

Coordinate conversion utility classes.

This module provides the classes CoordConverter and CoordSys2D. The former is used for a single axis, while the latter is used for 2-dimension cartesian coordinates.

Upon construction, these classes receives arguments defining the axes bounds, expressed in world coordinates, and whether the axes are inverted.

Then, one can use the methods to convert to and from Normalized Device Coordinates [0..1].

Example:

>>> import witkets as wtk
>>> coord_sys = CoordSys2D(10, 20, -30, -10, y_inverted=True)
>>> x, y = 15, -10
>>> xn, yn = coord_sys.to_ndc(x, y)
>>> x2, y2 = coord_sys.from_ndc(xn, yn)
>>> print('  Original Coords: %s' % ([x, y]))
  Original Coords: [15, -10]
>>> print('Normalized Coords: [%.1f, %.1f]' % (xn, yn))
Normalized Coords: [0.5, 0.0]
>>> print('  Loopback Coords: %s' % ([x2, y2]))
  Loopback Coords: [15.0, -10.0]

class witkets.coordsys.CoordConverter(minval, maxval, inverted=False)

Coordinate conversions to/from Normalized Device Coordinates.

from_ndc(an)

Get coordinate from normalized device coordinates [0..1]

in_range(a)

Check if value is within the bounds for this coordinate system.

property inverted

Whether axis direction is inverted (read-only).

property maxval

Maximum value (read-only).

property minval

Minimum value (read-only).

to_ndc(a)

Convert coordinate to normalized device coordinate [0..1]

class witkets.coordsys.CoordSys2D(x_min, x_max, y_min, y_max, x_inverted=False, y_inverted=False)

Pair of coordinate converters for X and Y

from_ndc(xn, yn)

Get coordinates from normalized device coordinates [0..1]

in_range(x, y)

Check if value is within the range.

to_ndc(x, y)

Convert a point to normalized device coordinates [0..1]