Dragging whole object versus individual points

Moving a graphics object as a whole, or refining individual data points.

• Features:

  • Graphics-driven assignments

  • Directing inverse assignments of binary operators

  • Dragging individual points versus whole object

• Try me:

  • Try dragging the ‘Move me!’ star - it will move as a whole.

  • Try dragging the ‘Change me!’ star - it will change individual points.

from pyquibbler import iquib, initialize_quibbler, q
initialize_quibbler()
import matplotlib.pyplot as plt
import numpy as np
%matplotlib tk

# Figure setup:
fig1 = plt.figure(figsize=(4, 4))
ax = fig1.gca()
ax.axis('square')
ax.axis([0, 12, 0, 12]);

# Define star coordinates:
nPoints = iquib(5)
dtet = 2 * np.pi / (2 * nPoints)
tet = np.arange(0.5 * np.pi, 2.5 * np.pi, dtet)
rR = np.array([1.5, 0.7])
rs = np.tile(rR, (nPoints,))
x_star = np.cos(tet) * rs
y_star = np.sin(tet) * rs;

# Allow changing the coordinates:
x_star.allow_overriding = True
y_star.allow_overriding = True

# Close the shapes by connecting the last point to the first point
x_star_circ = np.concatenate([x_star, x_star[[0]]])
y_star_circ = np.concatenate([y_star, y_star[[0]]])

# Define and draw movable star:
x_center_movable = iquib(7.)
y_center_movable = iquib(5.)

# using x_center_movable as the first argument in the summation
# (to which the inverse-assignment is channeled):
x_movable_star = x_center_movable + x_star_circ
y_movable_star = y_center_movable + y_star_circ
ax.text(x_center_movable,
        y_center_movable + np.min(y_star_circ) - 0.2,
        'Move me!', ha='center', va='top')
ax.plot(x_movable_star, y_movable_star, linewidth=2, color='m');

# Define and draw changeable star:
x_center_fixed = iquib(2.)
y_center_fixed = iquib(8.)

# using x_star_circ as the first argument in the summation
x_changeable_star = x_star_circ + x_center_fixed
y_changeable_star = y_star_circ + y_center_fixed
ax.text(x_center_fixed,
        y_center_fixed + np.min(y_star_circ) - 0.2,
        'Change me!', ha='center', va='top')
ax.plot(x_changeable_star, y_changeable_star, linewidth=2, color='c');

ax.set_title(q('{:.1f},{:.1f}'.format, x_center_movable, y_center_movable));