def spline_insert_knot():
dwg = ezdxf.new('R2000')
ezdxf.setup_linetypes(dwg)
msp = dwg.modelspace()
def add_spline(control_points, color=3, knots=None):
msp.add_polyline2d(control_points,
dxfattribs={
'color': color,
'linetype': 'DASHED'
})
msp.add_open_spline(control_points,
degree=3,
knots=knots,
dxfattribs={'color': color})
control_points = Vector.list([(0, 0), (10, 20), (30, 10), (40, 10),
(50, 0), (60, 20), (70, 50), (80, 70)])
add_spline(control_points, color=3, knots=None)
bspline = BSpline(control_points, order=4)
bspline.insert_knot(bspline.max_t / 2)
add_spline(bspline.control_points, color=4, knots=bspline.knot_values())
if dwg.validate():
dwg.saveas("Spline_R2000_spline_insert_knot.dxf")
def test_basis_vector_N_ip():
degree = 3
fit_points = Vector.list(POINTS2) # data points D
n = len(fit_points) - 1
t_vector = list(uniform_t_vector(fit_points))
knots = list(control_frame_knots(n, degree, t_vector))
should_count = len(fit_points) - 2 # target control point count
h = should_count - 1
spline = Basis(knots, order=degree + 1, count=len(fit_points))
matrix_N = [spline.basis(t) for t in t_vector]
for k in range(1, n):
basis_vector = bspline_basis_vector(u=t_vector[k],
count=len(fit_points),
degree=degree,
knots=knots)
for i in range(1, h):
assert is_close(matrix_N[k][i], basis_vector[i])
def spline_control_frame_approximation():
dwg = ezdxf.new('R2000')
ezdxf.setup_linetypes(dwg)
fit_points = Vector.list([(0, 0), (10, 20), (30, 10), (40, 10), (50, 0),
(60, 20), (70, 50), (80, 70), (65, 75)])
msp = dwg.modelspace()
msp.add_polyline2d(fit_points, dxfattribs={'color': 2, 'linetype': 'DOT2'})
spline = bspline_control_frame_approx(fit_points,
count=7,
degree=3,
method='uniform')
msp.add_polyline2d(spline.control_points,
dxfattribs={
'color': 3,
'linetype': 'DASHED'
})
msp.add_open_spline(spline.control_points,
degree=spline.degree,
dxfattribs={'color': 3})
msp.add_spline(fit_points, degree=3, dxfattribs={'color': 1})
if dwg.validate():
dwg.saveas("Spline_R2000_spline_control_frame_approximation.dxf")
from ezdxf.algebra import Vector, Matrix44
next_frame = Matrix44.translate(0, 5, 0)
right_frame = Matrix44.translate(10, 0, 0)
NAME = 'spline.dxf'
dwg = ezdxf.new('R2000')
msp = dwg.modelspace()
def draw(points):
for point in points:
msp.add_circle(radius=0.1, center=point, dxfattribs={'color': 1})
spline_points = Vector.list([(1., 1.), (2.5, 3.), (4.5, 2.), (6.5, 4.)])
# fit points
draw(spline_points)
Spline(spline_points).render_as_fit_points(
msp, method='distance',
dxfattribs={'color': 2}) # curve with definition points as fit points
Spline(spline_points).render_as_fit_points(msp,
method='uniform',
dxfattribs={'color': 3})
Spline(spline_points).render_as_fit_points(msp,
method='centripetal',
dxfattribs={'color':
4}) # distance ^ 1/2
Spline(spline_points).render_as_fit_points(msp,
method='centripetal',