def test__approx_QQ_pol_lst(self):
ring = PolyRing('x,y,z', True).ext_num_field('t^2 - 3')
x, y, z = ring.gens()
a0 = ring.root_gens()[0]
q2 = sage_QQ(1) / 2
pol_lst = [x * y * a0 + z**2 + q2 * y**2 - q2 - a0 * x, a0, -a0 * x]
out_lst = OrbRing.approx_QQ_pol_lst(pol_lst, 1)
c = sage_QQ(3900231685776981) / 2251799813685248
print(out_lst)
assert out_lst[0] == x * y * c + z**2 + q2 * y**2 - q2 - c * x
assert out_lst[1] == c
assert out_lst[2] == -c * x
def test__subs( self ):
ring = PolyRing( 'x,y,z', True )
ring.ext_num_field( 't^2 + 1' )
ring.ext_num_field( 't^3 + a0' )
a0, a1 = ring.root_gens()
x, y, z = ring.gens()
pol_lst = [x ** 2 + a0 * y * z, y + a1 * z + x ]
ls = LinearSeries( pol_lst, ring )
assert str( ls.pol_lst ) == '[x^2 + a0*y*z, x + y + a1*z]'
ls.subs( {x: x + 1} )
assert str( ls.pol_lst ) == '[x^2 + a0*y*z + 2*x + 1, x + y + a1*z + 1]'
def test__ext_num_field(self):
ring = PolyRing('x,y,z', True)
assert str(ring) == 'QQ[x, y, z]'
ring.ext_num_field('t^2 + t + 1')
assert str(ring) == 'QQ( <a0|t^2 + t + 1> )[x, y, z]'
ring.ext_num_field('t^3 + t + a0 + 3')
assert str(
ring
) == 'QQ( <a0|t^2 + t + 1>, <a1|t^3 + t + a0 + 3>, <a2|t^2 + a1*t + a1^2 + 1> )[x, y, z]'
a = ring.root_gens()
x, y, z = ring.gens()
pol = x**3 + x + a[0] + 3
assert str(sage_factor(pol)) == '(x - a2) * (x - a1) * (x + a2 + a1)'
mat = list(pol.sylvester_matrix(y**2 + x**2, x))
assert str(
mat
) == '[(1, 0, 1, a0 + 3, 0), (0, 1, 0, 1, a0 + 3), (1, 0, y^2, 0, 0), (0, 1, 0, y^2, 0), (0, 0, 1, 0, y^2)]'
def usecase__roman_circles():
'''
We compute circles on a Roman surface.
'''
# parametrization of the Roman surface
#
p_lst = '[ z^2+x^2+y^2, -z*x, -x*y, z*y ]'
# we consider the stereographic projection from
# S^3 = { x in P^4 | -x0^2+x1^2+x2^2+x3^2+x4^2 = 0 }
# where the center of projection is (1:0:0:0:1):
# (x0:x1:x2:x3:x4) |---> (x0-x4:x1:x2:x3)
# inverse stereographic projection into 3-sphere
#
s_lst = '[ y0^2+y1^2+y2^2+y3^2, 2*y0*y1, 2*y0*y2, 2*y0*y3, -y0^2+y1^2+y2^2+y3^2 ]'
# compose p_lst with s_lst
#
ring = PolyRing('x,y,z,y0,y1,y2,y3')
x, y, z, y0, y1, y2, y3 = ring.gens()
p_lst = ring.coerce(p_lst)
s_lst = ring.coerce(s_lst)
dct = {y0: p_lst[0], y1: p_lst[1], y2: p_lst[2], y3: p_lst[3]}
sp_lst = [s.subs(dct) for s in s_lst]
NSTools.p('sp_lst =')
for sp in sp_lst:
NSTools.p('\t\t', sage_factor(sp))
NSTools.p('gcd(sp_lst) =', sage_gcd(sp_lst))
# determine base points
#
ring = PolyRing('x,y,z', True)
sp_lst = ring.coerce(sp_lst)
ls = LinearSeries(sp_lst, ring)
NSTools.p(ls.get_bp_tree())
# We expect that the basepoints come from the intersection
# of the Roman surface with the absolute conic:
# A = { (y0:y1:y2:y3) in P^3 | y0=y1^2+y2^2+y3^2 = 0 }
#
# Circles are the image via p_lst of lines that pass through
# complex conjugate points.
#
ring = PolyRing('x,y,z',
False) # reinitialize ring with updated numberfield
a0, a1, a2, a3 = ring.root_gens()
# a0=(1-I*sqrt(3)) with conjugate a0-1 and minimal polynomial t^2-t+1
# we compute candidate classes of circles
#
h = Div.new('4e0-e1-e2-e3-e4-e5-e6-e7-e8')
div_lst = get_divs(h, 2, -2, False) + get_divs(h, 2, -1, False)
NSTools.p('Classes of circles up to permutation:')
for c in div_lst:
NSTools.p('\t\t', c)
# We recover the preimages of circles in the Roman surface
# under the map p_lst, by constructing for each candidate
# class the corresponding linear series.
# 2e0-e1-e2-e3-e4-e5-e6-e7-e8
b = [(a0 - 1, -a0), (-a0, a0 - 1)]
b += [(-a0 + 1, a0), (a0, -a0 + 1)]
b += [(a0 - 1, a0), (-a0, -a0 + 1)]
b += [(-a0 + 1, -a0), (a0, a0 - 1)]
bp_tree = BasePointTree()
for i in range(6):
bp_tree.add('z', b[i], 1)
NSTools.p('basepoints =', b)
NSTools.p(LinearSeries.get([2], bp_tree))
# e0-e1-e2
b = [(a0 - 1, -a0), (-a0, a0 - 1)]
bp_tree = BasePointTree()
bp = bp_tree.add('z', b[0], 1)
bp = bp_tree.add('z', b[1], 1)
NSTools.p('basepoints =', b)
NSTools.p(LinearSeries.get([1], bp_tree))
# e0-e3-e4
b = [(-a0 + 1, a0), (a0, -a0 + 1)]
bp_tree = BasePointTree()
bp = bp_tree.add('z', b[0], 1)
bp = bp_tree.add('z', b[1], 1)
NSTools.p('basepoints =', b)
NSTools.p(LinearSeries.get([1], bp_tree))
# e0-e5-e6
b = [(a0 - 1, a0), (-a0, -a0 + 1)]
bp_tree = BasePointTree()
bp = bp_tree.add('z', b[0], 1)
bp = bp_tree.add('z', b[1], 1)
NSTools.p('basepoints =', b)
NSTools.p(LinearSeries.get([1], bp_tree))
# e0-e7-e8
b = [(-a0 + 1, -a0), (a0, a0 - 1)]
bp_tree = BasePointTree()
bp = bp_tree.add('z', b[0], 1)
bp = bp_tree.add('z', b[1], 1)
NSTools.p('basepoints =', b)
NSTools.p(LinearSeries.get([1], bp_tree))
return
def CH1_cyclide():
'''
Creates povray image of a CH1 cyclide, which is
an inversion of a Circular Hyperboloid of 1 sheet.
'''
# Construct a trigonometric parametrization by rotating a circle.
r, R = 1, 1
c0, s0, c1, s1 = sage_var('c0,s0,c1,s1')
x, y, v, w, a0 = sage_var('x,y,v,w,a0')
q2 = sage_QQ(1) / 2
MX = sage_matrix([(1, 0, 0), (0, c1, s1), (0, -s1, c1)])
MXc = MX.subs({c1: a0, s1: a0}) # a0=1/sqrt(2)=cos(pi/4)=sin(pi/4)
MZ = sage_matrix([(c1, s1, 0), (-s1, c1, 0), (0, 0, 1)])
V = sage_vector([r * c0, 0, r * s0])
V = MXc * V
V[0] = V[0] + R
pmz_AB_lst = list(MZ * V)
OrbTools.p('V =', V)
OrbTools.p('pmz_AB_lst =', pmz_AB_lst)
for pmz in pmz_AB_lst:
OrbTools.p('\t\t', sage_factor(pmz))
# Convert the trigonometric parametrization to a rational parametrization
# We convert via the following formulas,
#
# cos(s) = (y^2-x^2) / (y^2+x^2)
# sin(s) = 2*x*y / (y^2+x^2)
# y=1; x = arctan( s/2 )
#
C0 = (y**2 - x**2) / (y**2 + x**2)
S0 = 2 * x * y / (y**2 + x**2)
C1 = (w**2 - v**2) / (w**2 + v**2)
S1 = 2 * v * w / (w**2 + v**2)
den = (y**2 + x**2) * (w**2 + v**2)
dct = {c0: C0, s0: S0, c1: C1, s1: S1}
pmz_lst = [den] + [(elt.subs(dct) * den).simplify_full()
for elt in list(MZ * V)]
OrbTools.p('pmz_lst =', pmz_lst)
for pmz in pmz_lst:
OrbTools.p('\t\t', sage_factor(pmz))
# do a basepoint analysis on the rational parametrization
# The True argument is for resetting the number field to QQ!
ring = PolyRing('x,y,v,w', True).ext_num_field('t^2-1/2')
ls = LinearSeries([str(pmz) for pmz in pmz_lst], ring)
OrbTools.p(ls.get_bp_tree())
# construct linear series for families of conics
ring = PolyRing(
'x,y,v,w') # construct polynomial ring over new ground field
OrbTools.p(ring)
x, y, v, w = ring.gens()
a0, a1 = ring.root_gens()
p1 = ['xv', (0, 2 * a0 * a1)]
p2 = ['xv', (0, -2 * a0 * a1)]
p3 = ['xv', (a1, 2 * a0 * a1)]
p4 = ['xv', (-a1, -2 * a0 * a1)]
bpt_1234 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_1234.add(p1[0], p1[1], 1)
bpt_1234.add(p2[0], p2[1], 1)
bpt_1234.add(p3[0], p3[1], 1)
bpt_1234.add(p4[0], p4[1], 1)
bpt_12 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_12.add(p1[0], p1[1], 1)
bpt_12.add(p2[0], p2[1], 1)
bpt_34 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_34.add(p3[0], p3[1], 1)
bpt_34.add(p4[0], p4[1], 1)
ls_22 = LinearSeries.get([2, 2], bpt_1234) # |2(l1+l2)-e1-e2-e3-e4|
ls_21 = LinearSeries.get([2, 1], bpt_1234)
ls_12 = LinearSeries.get([1, 2], bpt_1234)
ls_11a = LinearSeries.get([1, 1], bpt_12)
ls_11b = LinearSeries.get([1, 1], bpt_34)
OrbTools.p('linear series 22 =\n', ls_22)
OrbTools.p('linear series 21 =\n', ls_21)
OrbTools.p('linear series 12 =\n', ls_12)
OrbTools.p('linear series 11a =\n', ls_11a)
OrbTools.p('linear series 11b =\n', ls_11b)
# compute reparametrization from the linear series of families
ring = PolyRing(
'x,y,v,w,c0,s0,c1,s1') # construct polynomial ring with new generators
OrbTools.p(ring)
x, y, v, w, c0, s0, c1, s1 = ring.gens()
a0, a1 = ring.root_gens()
pmz_AB_lst = [1] + ring.coerce(pmz_AB_lst)
pmz_lst = ring.coerce(pmz_lst)
X = 1 - s0
Y = c0
V = 1 - s1
W = c1
CB_dct = {
x: X,
y: Y,
v: W * X - 2 * a0 * V * Y,
w: V * X + 2 * a0 * W * Y
}
pmz_CB_lst = [pmz.subs(CB_dct) for pmz in pmz_lst] # CB 11b
# output
OrbTools.p('pmz_AB_lst =\n', pmz_AB_lst)
OrbTools.p('pmz_CB_lst =\n', pmz_CB_lst)
# approximate by map defined over rational numbers
ci_idx = 0 # index defining the complex embedding
OrbTools.p('complex embeddings =')
for i in range(len(a0.complex_embeddings())):
a0q = OrbRing.approx_QQ_coef(a0, i)
OrbTools.p('\t\t' + str(i) + ' =', a0q, sage_n(a0q))
pmz_AB_lst = OrbRing.approx_QQ_pol_lst(pmz_AB_lst, ci_idx)
pmz_CB_lst = OrbRing.approx_QQ_pol_lst(pmz_CB_lst, ci_idx)
# mathematica input
ms = ''
for pmz, AB in [(pmz_lst, 'ZZ'), (pmz_AB_lst, 'AB'), (pmz_CB_lst, 'CB')]:
s = 'pmz' + AB + '=' + str(pmz) + ';'
s = s.replace('[', '{').replace(']', '}')
ms += '\n' + s
OrbTools.p('Mathematica input =', ms)
# PovInput ring cyclide
#
pin = PovInput()
pin.path = './' + get_time_str() + '_CH1_cyclide/'
pin.fname = 'orb'
pin.scale = 1
pin.cam_dct['location'] = (0, -5, 0)
pin.cam_dct['lookat'] = (0, 0, 0)
pin.cam_dct['rotate'] = (20, 0, 0)
pin.shadow = True
pin.light_lst = [(1, 0, 0), (0, 1, 0), (0, 0, 1), (-1, 0, 0), (0, -1, 0),
(0, 0, -1), (10, 0, 0), (0, 10, 0), (0, 0, 10),
(-10, 0, 0), (0, -10, 0), (0, 0, -10)]
pin.axes_dct['show'] = False
pin.axes_dct['len'] = 1.2
pin.height = 400
pin.width = 800
pin.quality = 11
pin.ani_delay = 10
pin.impl = None
pin.pmz_dct['A'] = (pmz_AB_lst, 0)
pin.pmz_dct['B'] = (pmz_AB_lst, 1)
pin.pmz_dct['C'] = (pmz_CB_lst, 0)
pin.pmz_dct['FA'] = (pmz_AB_lst, 0)
pin.pmz_dct['FB'] = (pmz_AB_lst, 1)
pin.pmz_dct['FC'] = (pmz_CB_lst, 0)
v0_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)]
v1_lst_A = [(sage_QQ(i) / 180) * sage_pi for i in range(180, 360, 10)]
v1_lst_B = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 180, 10)]
v1_lst_C = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 180, 10)]
v1_lst_FA = [(sage_QQ(i) / 180) * sage_pi for i in range(180, 360, 2)]
v1_lst_FB = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 180, 2)]
v1_lst_FC = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 180, 2)]
prec = 50
pin.curve_dct['A'] = {
'step0': v0_lst,
'step1': v1_lst_A,
'prec': prec,
'width': 0.03
}
pin.curve_dct['B'] = {
'step0': v0_lst,
'step1': v1_lst_B,
'prec': prec,
'width': 0.03
}
pin.curve_dct['C'] = {
'step0': v0_lst,
'step1': v1_lst_C,
'prec': prec,
'width': 0.03
}
pin.curve_dct['FA'] = {
'step0': v0_lst,
'step1': v1_lst_FA,
'prec': prec,
'width': 0.02
}
pin.curve_dct['FB'] = {
'step0': v0_lst,
'step1': v1_lst_FB,
'prec': prec,
'width': 0.02
}
pin.curve_dct['FC'] = {
'step0': v0_lst,
'step1': v1_lst_FC,
'prec': prec,
'width': 0.02
}
col_A = (0.6, 0.4, 0.1, 0.0)
col_B = (0.1, 0.15, 0.0, 0.0)
col_C = (0.2, 0.3, 0.2, 0.0)
colFF = (0.1, 0.1, 0.1, 0.0)
pin.text_dct['A'] = [True, col_A, 'phong 0.2 phong_size 5']
pin.text_dct['B'] = [True, col_B, 'phong 0.2 phong_size 5']
pin.text_dct['C'] = [True, col_C, 'phong 0.2 phong_size 5']
pin.text_dct['FA'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FB'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FC'] = [True, colFF, 'phong 0.2 phong_size 5']
# raytrace image/animation
create_pov(pin, ['A', 'B', 'C'])
create_pov(pin, ['A', 'B', 'C', 'FA', 'FB', 'FC'])
create_pov(pin, ['A', 'B', 'FA', 'FB'])
create_pov(pin, ['B', 'C', 'FA', 'FB'])
def dp6_smooth():
'''
Creates povray image of the projection of a smooth sextic del Pezzo
surface in S^5. This surface contains 3 families of conics that
form a hexagonal web.
'''
# compute parametrizations of canonical model
a0 = PolyRing('x,y,v,w', True).ext_num_field('t^2 + 1').root_gens()[0]
bp_tree = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bp = bp_tree.add('xv', (-a0, a0), 1)
bp = bp_tree.add('xv', (a0, -a0), 1)
ls_AB = LinearSeries.get([2, 2], bp_tree)
ls_CB = LinearSeries.get([1, 1], bp_tree)
# compute surface in quadric of signature (6,1)
c_lst = [-1, -1, 0, 0, 0, -1, 1, 0, -1, -1, -1]
dct = get_surf(ls_AB, (6, 1), c_lst)
# compute projection to P^3
U, J = dct['UJ']
U.swap_rows(0, 6)
J.swap_columns(0, 6)
J.swap_rows(0, 6)
approxU = approx_QQ(U)
P = get_prj_mat(4, 7, 0)
P[0, 6] = -1
P[3, 3] = 0
P[3, 4] = 1
P = P * approxU
f_xyz, pmz_AB_lst = get_proj(dct['imp_lst'], dct['pmz_lst'], P)
# compute reparametrization
ring = PolyRing(
'x,y,v,w,c0,s0,c1,s1') # construct polynomial ring with new generators
x, y, v, w, c0, s0, c1, s1 = ring.gens()
X = 1 - s0
Y = c0
# see get_S1xS1_pmz()
V = 1 - s1
W = c1
CB_dct = {x: X, y: Y, v: X * W + Y * V, w: X * V - Y * W}
pmz_CB_lst = [p.subs(CB_dct) for p in ring.coerce(ls_AB.pol_lst)]
pmz_CB_lst = list(P * dct['Q'] * sage_vector(pmz_CB_lst))
# set PovInput as container
# put very low quality for testing purposes
pin = PovInput()
pin.path = './' + get_time_str() + '_dp6_smooth/'
pin.fname = 'orb'
pin.scale = 1
pin.cam_dct['location'] = (0, 0, sage_QQ(-21) / 10)
pin.cam_dct['lookat'] = (0, 0, 0)
pin.cam_dct['rotate'] = (310, 0, 0)
pin.shadow = True
pin.light_lst = [(0, 0, -4), (0, -4, 0), (-4, 0, 0), (0, 4, 0), (4, 0, 0),
(-5, -5, -5), (5, 5, -5), (-5, 5, -5), (5, -5, -5)]
pin.axes_dct['show'] = False
pin.axes_dct['len'] = 1.2
pin.height = 400
pin.width = 800
pin.quality = 11
pin.ani_delay = 1
pin.impl = None
v0_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)]
v1_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 15)]
v1_F_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 1)]
pin.pmz_dct['A'] = (pmz_AB_lst, 0)
pin.pmz_dct['B'] = (pmz_AB_lst, 1)
pin.pmz_dct['C'] = (pmz_CB_lst, 0)
pin.pmz_dct['FA'] = (pmz_AB_lst, 0)
pin.pmz_dct['FB'] = (pmz_AB_lst, 1)
pin.pmz_dct['FC'] = (pmz_CB_lst, 0)
pin.curve_dct['A'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.018
}
pin.curve_dct['B'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.018
}
pin.curve_dct['C'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.018
}
pin.curve_dct['FA'] = {
'step0': v0_lst,
'step1': v1_F_lst,
'prec': 10,
'width': 0.003
}
pin.curve_dct['FB'] = {
'step0': v0_lst,
'step1': v1_F_lst,
'prec': 10,
'width': 0.003
}
pin.curve_dct['FC'] = {
'step0': v0_lst,
'step1': v1_F_lst,
'prec': 10,
'width': 0.003
}
# ( 0.4, 0.0, 0.0, 0.0 ), ( 0.2, 0.3, 0.2, 0.0 ), ( 0.8, 0.6, 0.2, 0.0 )
col_A = rgbt2pov((75, 102, 0, 0)) # green /
col_B = rgbt2pov((74, 33, 0, 0)) # brown -
col_C = rgbt2pov((28, 125, 154, 0)) # blue \
colFF = rgbt2pov((179, 200, 217, 0)) # light blue
pin.text_dct['A'] = [True, col_A, 'phong 0.2']
pin.text_dct['B'] = [True, col_B, 'phong 0.2']
pin.text_dct['C'] = [True, col_C, 'phong 0.2']
pin.text_dct['FA'] = [True, colFF, 'phong 0.8']
pin.text_dct['FB'] = [True, colFF, 'phong 0.8']
pin.text_dct['FC'] = [True, colFF, 'phong 0.8']
# raytrace image/animation
create_pov(pin, ['A', 'B', 'C'])
create_pov(pin, ['A', 'B', 'C', 'FA', 'FB', 'FC'])
create_pov(pin, ['A', 'FA', 'FB', 'FC'])
create_pov(pin, ['B', 'FA', 'FB', 'FC'])
create_pov(pin, ['C', 'FA', 'FB', 'FC'])
def perseus_cyclide():
'''
Creates povray image of the Perseus cyclide.
'''
# We first construct a trigonometric parametrization
# by rotating a circle.
# cos(pi/3) = 1/2
# sin(pi/3) = sqrt(3)/2
#
r, R = 1, 2
c0, s0, c1, s1 = sage_var('c0,s0,c1,s1')
x, y, v, w, a0 = sage_var('x,y,v,w,a0')
q2 = sage_QQ(1) / 2
MZ = sage_matrix([(c1, s1, 0), (-s1, c1, 0), (0, 0, 1)])
MZc = MZ.subs({c1: q2, s1: q2 * a0})
V = sage_vector([r * c0, 0, r * s0])
V = MZc * V
V[0] = V[0] + R
pmz_AB_lst = list(MZ * V)
OrbTools.p('V =', V)
OrbTools.p('pmz_AB_lst =', pmz_AB_lst)
for pmz in pmz_AB_lst:
OrbTools.p('\t\t', sage_factor(pmz))
# We convert the trigonometric parametrization to a
# rational parametrization, via the following formulas:
#
# cos(s) = (y^2-x^2) / (y^2+x^2)
# sin(s) = 2*x*y / (y^2+x^2)
# y=1; x = arctan( s/2 )
#
C0 = (y**2 - x**2) / (y**2 + x**2)
S0 = 2 * x * y / (y**2 + x**2)
C1 = (w**2 - v**2) / (w**2 + v**2)
S1 = 2 * v * w / (w**2 + v**2)
den = (y**2 + x**2) * (w**2 + v**2)
dct = {c0: C0, s0: S0, c1: C1, s1: S1}
pmz_lst = [den] + [(elt.subs(dct) * den).simplify_full()
for elt in list(MZ * V)]
OrbTools.p('pmz_lst =', pmz_lst)
for pmz in pmz_lst:
OrbTools.p('\t\t', sage_factor(pmz))
# do a basepoint analysis on the rational parametrization
#
ring = PolyRing('x,y,v,w', True).ext_num_field('t^2-3')
ls = LinearSeries([str(pmz) for pmz in pmz_lst], ring)
OrbTools.p(ls.get_bp_tree())
# construct linear series for families of conics
#
ring = PolyRing(
'x,y,v,w') # construct polynomial ring over new ground field
OrbTools.p(ring)
x, y, v, w = ring.gens()
a0, a1, a2, a3 = ring.root_gens()
p1 = ['xv', (-a3, a1)]
p2 = ['xv', (-a2, -a1)]
p3 = ['xv', (a3, a1)]
p4 = ['xv', (a2, -a1)]
bpt_1234 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_1234.add(p1[0], p1[1], 1)
bpt_1234.add(p2[0], p2[1], 1)
bpt_1234.add(p3[0], p3[1], 1)
bpt_1234.add(p4[0], p4[1], 1)
bpt_12 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_12.add(p1[0], p1[1], 1)
bpt_12.add(p2[0], p2[1], 1)
bpt_34 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_34.add(p3[0], p3[1], 1)
bpt_34.add(p4[0], p4[1], 1)
ls_22 = LinearSeries.get([2, 2], bpt_1234)
ls_21 = LinearSeries.get([2, 1], bpt_1234)
ls_12 = LinearSeries.get([1, 2], bpt_1234)
ls_11a = LinearSeries.get([1, 1], bpt_12)
ls_11b = LinearSeries.get([1, 1], bpt_34)
OrbTools.p('linear series 22 =\n', ls_22)
OrbTools.p('linear series 21 =\n', ls_21)
OrbTools.p('linear series 12 =\n', ls_12)
OrbTools.p('linear series 11a =\n', ls_11a)
OrbTools.p('linear series 11b =\n', ls_11b)
# compute reparametrization from the linear series of families
ring = PolyRing('x,y,v,w,c0,s0,c1,s1')
OrbTools.p(ring)
x, y, v, w, c0, s0, c1, s1 = ring.gens()
a0, a1, a2, a3 = ring.root_gens()
pmz_AB_lst = [1] + ring.coerce(pmz_AB_lst)
pmz_lst = ring.coerce(pmz_lst)
q2 = sage_QQ(1) / 2
a = 2 * a0 / 3
b = (-a0 * a1 / 3 - q2) * a3
c = (a0 * a1 / 3 - q2) * a2
d = (a1 / 2 - a0 / 3) * a3
e = (-a1 / 2 - a0 / 3) * a2
bc = b + c
de = d + e
X = 1 - s0
Y = c0
V = 1 - s1
W = c1
CB_dct = {
x: X,
y: Y,
v: W * X + bc * W * Y - de * V * Y,
w: V * X + bc * V * Y + de * W * Y
}
DB_dct = {
x: X,
y: Y,
v: W * X - bc * W * Y + de * V * Y,
w: V * X - bc * V * Y - de * W * Y
}
EB_dct = {
x: X,
y: Y,
v: W * X**2 + W * Y**2 - a * V * Y**2,
w: V * X**2 + V * Y**2 + a * W * Y**2
}
pmz_CB_lst = [pmz.subs(CB_dct) for pmz in pmz_lst] # CB 11a
pmz_DB_lst = [pmz.subs(DB_dct) for pmz in pmz_lst] # CB 11b
pmz_EB_lst = [pmz.subs(EB_dct) for pmz in pmz_lst] # CB 21
# output
OrbTools.p('pmz_AB_lst =\n', pmz_AB_lst)
OrbTools.p('pmz_CB_lst =\n', pmz_CB_lst)
OrbTools.p('pmz_DB_lst =\n', pmz_DB_lst)
OrbTools.p('pmz_EB_lst =\n', pmz_EB_lst)
# approximate by map defined over rational numbers
ci_idx = 5 # index defining the complex embedding
pmz_AB_lst = OrbRing.approx_QQ_pol_lst(pmz_AB_lst, ci_idx)
pmz_CB_lst = OrbRing.approx_QQ_pol_lst(pmz_CB_lst, ci_idx)
pmz_DB_lst = OrbRing.approx_QQ_pol_lst(pmz_DB_lst, ci_idx)
pmz_EB_lst = OrbRing.approx_QQ_pol_lst(pmz_EB_lst, ci_idx)
# mathematica input
ms = ''
for pmz, AB in [(pmz_lst, 'ZZ'), (pmz_AB_lst, 'AB'), (pmz_CB_lst, 'CB'),
(pmz_DB_lst, 'DB'), (pmz_EB_lst, 'EB')]:
s = 'pmz' + AB + '=' + str(pmz) + ';'
s = s.replace('[', '{').replace(']', '}')
ms += '\n' + s
OrbTools.p('Mathematica input =', ms)
# PovInput ring cyclide
#
pin = PovInput()
pin.path = './' + get_time_str() + '_perseus_cyclide/'
pin.fname = 'orb'
pin.scale = 1
pin.cam_dct['location'] = (0, 7, 0)
pin.cam_dct['lookat'] = (0, 0, 0)
pin.cam_dct['rotate'] = (45, 0, 0)
pin.shadow = True
pin.light_lst = [(0, 0, -10), (0, -10, 0), (-10, 0, 0), (0, 0, 10),
(0, 10, 0), (10, 0, 0)]
pin.axes_dct['show'] = False
pin.axes_dct['len'] = 1.2
pin.height = 400
pin.width = 800
pin.quality = 11
pin.ani_delay = 10
pin.impl = None
pin.pmz_dct['A'] = (pmz_AB_lst, 0)
pin.pmz_dct['B'] = (pmz_AB_lst, 1)
pin.pmz_dct['C'] = (pmz_CB_lst, 0)
pin.pmz_dct['D'] = (pmz_DB_lst, 0)
pin.pmz_dct['E'] = (pmz_EB_lst, 0)
pin.pmz_dct['FA'] = (pmz_AB_lst, 0)
pin.pmz_dct['FB'] = (pmz_AB_lst, 1)
pin.pmz_dct['FC'] = (pmz_CB_lst, 0)
pin.pmz_dct['FD'] = (pmz_DB_lst, 0)
pin.pmz_dct['FE'] = (pmz_EB_lst, 0)
v0_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)]
v1_lst_A = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)] # 5
v1_lst_B = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 15)]
v1_lst_C = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 36)]
v1_lst_D = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 36)]
v1_lst_E = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)] # 5
v1_lst_F = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 1)]
prec = 50
pin.curve_dct['A'] = {
'step0': v0_lst,
'step1': v1_lst_A,
'prec': prec,
'width': 0.04
}
pin.curve_dct['B'] = {
'step0': v0_lst,
'step1': v1_lst_B,
'prec': prec,
'width': 0.04
}
pin.curve_dct['C'] = {
'step0': v0_lst,
'step1': v1_lst_C,
'prec': prec,
'width': 0.05
}
pin.curve_dct['D'] = {
'step0': v0_lst,
'step1': v1_lst_D,
'prec': prec,
'width': 0.05
}
pin.curve_dct['E'] = {
'step0': v0_lst,
'step1': v1_lst_E,
'prec': prec,
'width': 0.04
}
pin.curve_dct['FA'] = {
'step0': v0_lst,
'step1': v1_lst_F,
'prec': prec,
'width': 0.01
}
pin.curve_dct['FB'] = {
'step0': v0_lst,
'step1': v1_lst_F,
'prec': prec,
'width': 0.01
}
pin.curve_dct['FC'] = {
'step0': v0_lst,
'step1': v1_lst_F,
'prec': prec,
'width': 0.01
}
pin.curve_dct['FD'] = {
'step0': v0_lst,
'step1': v1_lst_F,
'prec': prec,
'width': 0.01
}
pin.curve_dct['FE'] = {
'step0': v0_lst,
'step1': v1_lst_F,
'prec': prec,
'width': 0.01
}
col_A = (0.6, 0.0, 0.0, 0.0) # red
col_B = (0.8, 0.6, 0.2, 0.0) # beige
col_C = (0.6, 0.0, 0.0, 0.0
) # red *** rgbt2pov( ( 74, 33, 0, 0 ) ) # brown
col_D = (0.2, 0.6, 0.0, 0.0
) # green *** rgbt2pov( ( 28, 125, 154, 0 ) ) # blue
col_E = (0.2, 0.6, 0.0, 0.0) # green
colFF = (0.1, 0.1, 0.1, 0.0)
pin.text_dct['A'] = [True, col_A, 'phong 0.2 phong_size 5']
pin.text_dct['B'] = [True, col_B, 'phong 0.2 phong_size 5']
pin.text_dct['C'] = [True, col_C, 'phong 0.2 phong_size 5']
pin.text_dct['D'] = [True, col_D, 'phong 0.2 phong_size 5']
pin.text_dct['E'] = [True, col_E, 'phong 0.2 phong_size 5']
pin.text_dct['FA'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FB'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FC'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FD'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FE'] = [True, colFF, 'phong 0.2 phong_size 5']
# raytrace image/animation
create_pov(pin, ['C', 'D', 'FC', 'FD'])
create_pov(pin, ['A', 'B', 'FC', 'FD'])
create_pov(pin, ['E', 'B', 'FC', 'FD'])
def blum_cyclide():
'''
Construct a povray image of 6 families of circles on a smooth Darboux cyclide.
This surface is also known as the Blum cyclide.
'''
# construct dct
a0 = PolyRing( 'x,y,v,w', True ).ext_num_field( 't^2 + 1' ).root_gens()[0] # i
bpt_1234 = BasePointTree( ['xv', 'xw', 'yv', 'yw'] )
bpt_1234.add( 'xv', ( -1 * a0, 1 * a0 ), 1 ) # e1
bpt_1234.add( 'xv', ( 1 * a0, -1 * a0 ), 1 ) # e2
bpt_1234.add( 'xw', ( -2 * a0, 2 * a0 ), 1 ) # e3
bpt_1234.add( 'xw', ( 2 * a0, -2 * a0 ), 1 ) # e4
bpt_12 = BasePointTree( ['xv', 'xw', 'yv', 'yw'] )
bpt_12.add( 'xv', ( -1 * a0, 1 * a0 ), 1 ) # e1
bpt_12.add( 'xv', ( 1 * a0, -1 * a0 ), 1 ) # e2
bpt_34 = BasePointTree( ['xv', 'xw', 'yv', 'yw'] )
bpt_34.add( 'xw', ( -2 * a0, 2 * a0 ), 1 ) # e3
bpt_34.add( 'xw', ( 2 * a0, -2 * a0 ), 1 ) # e4
ls_22 = LinearSeries.get( [2, 2], bpt_1234 ) # |2(l1+l2)-e1-e2-e3-e4|
ls_21 = LinearSeries.get( [2, 1], bpt_1234 )
ls_12 = LinearSeries.get( [1, 2], bpt_1234 )
ls_11a = LinearSeries.get( [1, 1], bpt_12 )
ls_11b = LinearSeries.get( [1, 1], bpt_34 )
OrbTools.p( 'linear series 22 =\n', ls_22 )
OrbTools.p( 'linear series 21 =\n', ls_21 )
OrbTools.p( 'linear series 12 =\n', ls_12 )
OrbTools.p( 'linear series 11a =\n', ls_11a )
OrbTools.p( 'linear series 11b =\n', ls_11b )
sig = ( 4, 1 )
pol_lst = ls_22.get_implicit_image()
# determine signature
x_lst = sage_PolynomialRing( sage_QQ, [ 'x' + str( i ) for i in range( sum( sig ) )] ).gens()
for pol in pol_lst:
if pol.degree() == 2:
M = sage_invariant_theory.quadratic_form( pol, x_lst ).as_QuadraticForm().matrix()
D, V = sage_matrix( sage_QQ, M ).eigenmatrix_right() # D has first all negative values on diagonal
cur_sig = ( len( [ d for d in D.diagonal() if d < 0 ] ), len( [ d for d in D.diagonal() if d > 0 ] ) )
else:
cur_sig = '[no signature]'
OrbTools.p( '\t\t', pol, cur_sig )
# obtain surface in sphere
coef_lst = [0, -1, -1]
dct = get_surf( ls_22, sig, coef_lst )
# construct projection matrix P
U, J = dct['UJ']
U.swap_rows( 0, 4 )
J.swap_columns( 0, 4 )
J.swap_rows( 0, 4 )
assert dct['M'] == approx_QQ( U.T * J * U )
approxU = approx_QQ( U )
P = sage_identity_matrix( 5 ).submatrix( 0, 0, 4, 5 )
P[0, 4] = -1;
P = P * approxU
OrbTools.p( ' approx_QQ( U ) =', list( approx_QQ( U ) ) )
OrbTools.p( ' approx_QQ( J ) =', list( approx_QQ( J ) ) )
OrbTools.p( ' P =', list( P ) )
# call get_proj
f_xyz, pmz_AB_lst = get_proj( dct['imp_lst'], dct['pmz_lst'], P )
f_xyz_deg_lst = [f_xyz.degree( sage_var( v ) ) for v in ['x', 'y', 'z']]
# compute reparametrization
ring = PolyRing( 'x,y,v,w,c0,s0,c1,s1' ) # construct polynomial ring with new generators
p_lst = ring.coerce( ls_22.pol_lst )
x, y, v, w, c0, s0, c1, s1 = ring.gens()
X = 1 - s0; Y = c0; # see get_S1xS1_pmz()
V = 1 - s1; W = c1;
CB_dct = { x:X, y:Y, v:X * W + Y * V, w: X * V - Y * W }
DB_dct = { x:X, y:Y, v:4 * X * W - Y * V, w: X * V + Y * W }
EB_dct = { x:X, y:Y, v:40 * W * X ** 2 + 25 * W * Y ** 2 + 24 * V * X * Y, w:40 * V * X ** 2 + 16 * V * Y ** 2 - 15 * W * X * Y }
AF_dct = { x:-10 * Y * V ** 2 - 25 * Y * W ** 2 + 9 * X * V * W, y:15 * X * V ** 2 + 24 * X * W ** 2 - 15 * Y * V * W, v:V, w:W }
pmz_CB_lst = list( P * sage_vector( [ p.subs( CB_dct ) for p in p_lst] ) )
pmz_DB_lst = list( P * sage_vector( [ p.subs( DB_dct ) for p in p_lst] ) )
pmz_EB_lst = list( P * sage_vector( [ p.subs( EB_dct ) for p in p_lst] ) )
pmz_AF_lst = list( P * sage_vector( [ p.subs( AF_dct ) for p in p_lst] ) )
# output
OrbTools.p( 'f_xyz =', f_xyz_deg_lst, '\n', f_xyz )
OrbTools.p( 'pmz_AB_lst =\n', pmz_AB_lst )
OrbTools.p( 'pmz_CB_lst =\n', pmz_CB_lst )
OrbTools.p( 'pmz_DB_lst =\n', pmz_DB_lst )
OrbTools.p( 'pmz_EB_lst =\n', pmz_EB_lst )
OrbTools.p( 'pmz_AF_lst =\n', pmz_AF_lst )
# mathematica
pmz_lst = [ ( pmz_AB_lst, 'AB' ),
( pmz_CB_lst, 'CB' ),
( pmz_DB_lst, 'DB' ),
( pmz_EB_lst, 'EB' ),
( pmz_AF_lst, 'AF' )]
OrbTools.p( 'Mathematica input for ParametricPlot3D:' )
for pmz, AB in pmz_lst:
s = 'pmz' + AB + '=' + str( pmz )
s = s.replace( '[', '{' ).replace( ']', '}' )
print( s )
# PovInput for Blum cyclide
#
pin = PovInput()
pin.path = './' + get_time_str() + '_blum_cyclide/'
pin.fname = 'orb'
pin.scale = 1
pin.cam_dct['location'] = ( 0, -7, 0 )
pin.cam_dct['lookat'] = ( 0, 0, 0 )
pin.cam_dct['rotate'] = ( 20, 180, 20 )
pin.shadow = True
pin.light_lst = [( 0, 0, -5 ), ( 0, -5, 0 ), ( -5, 0, 0 ),
( 0, 0, 5 ), ( 0, 5, 0 ), ( 5, 0, 0 ),
( -5, -5, -5 ), ( 5, -5, 5 ), ( -5, -5, 5 ), ( 5, -5, -5 ) ]
pin.axes_dct['show'] = False
pin.axes_dct['len'] = 1.2
pin.height = 400
pin.width = 800
pin.quality = 11
pin.ani_delay = 10
pin.impl = None
start0 = sage_QQ( 1 ) / 10 # step0=10 step1=15
v0_lst = [ start0 + ( sage_QQ( i ) / 180 ) * sage_pi for i in range( 0, 360, 10 )]
v1_lst = [ ( sage_QQ( i ) / 180 ) * sage_pi for i in range( 0, 360, 15 )]
v1_lst_F = [ start0 + ( sage_QQ( i ) / 360 ) * sage_pi for i in range( 0, 720, 1 )]
v1_lst_WE = [1.8, 2.3, 2.7, 3.1, 3.5, 3.8, 4.134, 4.31, 4.532, 4.7, 4.9, 5.08, 5.25, 5.405, 5.553, 5.7, 5.84]
v1_lst_WF = [1.69, 1.87, 2.07, 2.26, 2.5, 2.72, 2.96, 3.2, 3.42, 3.65, 3.81]
v1_lst_WD = [ 5.44, 5.56, 5.68, 5.81, 5.95, 6.1, 6.27, 6.474] # [5.01, 5.12, 5.22, 5.32,
v1_lst_SA = [6.5]; v1_lst_SE = [5.4];
v1_lst_SB = [5.95]; v1_lst_SF = [2.28];
v1_lst_SC = [4.83]; v1_lst_SD = [5.55];
pin.pmz_dct['A'] = ( pmz_AB_lst, 0 )
pin.pmz_dct['B'] = ( pmz_AB_lst, 1 )
pin.pmz_dct['C'] = ( pmz_CB_lst, 0 )
pin.pmz_dct['D'] = ( pmz_DB_lst, 0 )
pin.pmz_dct['E'] = ( pmz_EB_lst, 0 )
pin.pmz_dct['F'] = ( pmz_AF_lst, 1 )
pin.pmz_dct['WD'] = ( pmz_DB_lst, 0 )
pin.pmz_dct['WE'] = ( pmz_EB_lst, 0 )
pin.pmz_dct['WF'] = ( pmz_AF_lst, 1 )
pin.pmz_dct['SA'] = ( pmz_AB_lst, 0 )
pin.pmz_dct['SB'] = ( pmz_AB_lst, 1 )
pin.pmz_dct['SC'] = ( pmz_CB_lst, 0 )
pin.pmz_dct['SD'] = ( pmz_DB_lst, 0 )
pin.pmz_dct['SE'] = ( pmz_EB_lst, 0 )
pin.pmz_dct['SF'] = ( pmz_AF_lst, 1 )
pin.pmz_dct['FA'] = ( pmz_AB_lst, 0 )
pin.pmz_dct['FB'] = ( pmz_AB_lst, 1 )
pin.pmz_dct['FC'] = ( pmz_CB_lst, 0 )
pin.pmz_dct['FD'] = ( pmz_DB_lst, 0 )
pin.pmz_dct['FE'] = ( pmz_EB_lst, 0 )
pin.pmz_dct['FF'] = ( pmz_AF_lst, 1 )
pin.curve_dct['A'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['B'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['C'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['D'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['E'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['F'] = {'step0':v0_lst, 'step1':v1_lst, 'prec':10, 'width':0.05}
pin.curve_dct['WD'] = {'step0':v0_lst, 'step1':v1_lst_WD, 'prec':10, 'width':0.05}
pin.curve_dct['WE'] = {'step0':v0_lst, 'step1':v1_lst_WE, 'prec':10, 'width':0.05}
pin.curve_dct['WF'] = {'step0':v0_lst, 'step1':v1_lst_WF, 'prec':10, 'width':0.05}
pin.curve_dct['SA'] = {'step0':v0_lst, 'step1':v1_lst_SA, 'prec':10, 'width':0.05}
pin.curve_dct['SB'] = {'step0':v0_lst, 'step1':v1_lst_SB, 'prec':10, 'width':0.05}
pin.curve_dct['SC'] = {'step0':v0_lst, 'step1':v1_lst_SC, 'prec':10, 'width':0.05}
pin.curve_dct['SD'] = {'step0':v0_lst, 'step1':v1_lst_SD, 'prec':10, 'width':0.06}
pin.curve_dct['SE'] = {'step0':v0_lst, 'step1':v1_lst_SE, 'prec':10, 'width':0.05}
pin.curve_dct['SF'] = {'step0':v0_lst, 'step1':v1_lst_SF, 'prec':10, 'width':0.05}
pin.curve_dct['FA'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
pin.curve_dct['FB'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
pin.curve_dct['FC'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
pin.curve_dct['FD'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
pin.curve_dct['FE'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
pin.curve_dct['FF'] = {'step0':v0_lst, 'step1':v1_lst_F, 'prec':10, 'width':0.01}
col_A = rgbt2pov( ( 28, 125, 154, 0 ) ) # blue
col_B = rgbt2pov( ( 74, 33, 0, 0 ) ) # brown
col_C = rgbt2pov( ( 75, 102, 0, 0 ) ) # green
col_E = col_A
col_F = col_B
col_D = col_C
colFF = rgbt2pov( ( 179, 200, 217, 0 ) ) # light blue
pin.text_dct['A'] = [True, col_A, 'phong 0.2' ]
pin.text_dct['B'] = [True, col_B, 'phong 0.2' ]
pin.text_dct['C'] = [True, col_C, 'phong 0.2' ]
pin.text_dct['E'] = [True, col_E, 'phong 0.2' ]
pin.text_dct['F'] = [True, col_F, 'phong 0.2' ]
pin.text_dct['D'] = [True, col_D, 'phong 0.2' ]
pin.text_dct['WE'] = [True, col_E, 'phong 0.2' ]
pin.text_dct['WF'] = [True, col_F, 'phong 0.2' ]
pin.text_dct['WD'] = [True, col_D, 'phong 0.2' ]
pin.text_dct['SA'] = [True, col_A, 'phong 0.2' ]
pin.text_dct['SB'] = [True, col_B, 'phong 0.2' ]
pin.text_dct['SC'] = [True, col_C, 'phong 0.2' ]
pin.text_dct['SE'] = [True, col_E, 'phong 0.2' ]
pin.text_dct['SF'] = [True, col_F, 'phong 0.2' ]
pin.text_dct['SD'] = [True, col_D, 'phong 0.2' ]
pin.text_dct['FA'] = [True, colFF, 'phong 0.2' ]
pin.text_dct['FB'] = [True, colFF, 'phong 0.2' ]
pin.text_dct['FC'] = [True, colFF, 'phong 0.2' ]
pin.text_dct['FE'] = [True, colFF, 'phong 0.2' ]
pin.text_dct['FF'] = [True, colFF, 'phong 0.2' ]
pin.text_dct['FD'] = [True, colFF, 'phong 0.2' ]
# raytrace image/animation
F_lst = ['FA', 'FB', 'FC']
S_lst = ['SA', 'SB', 'SC', 'SD', 'SE', 'SF']
create_pov( pin, ['A', 'B', 'C'] )
create_pov( pin, ['A', 'B', 'C'] + F_lst )
create_pov( pin, ['WD', 'WE', 'WF'] )
create_pov( pin, ['WD', 'WE', 'WF'] + F_lst )
create_pov( pin, S_lst + F_lst )
# ABC - EFD
create_pov( pin, ['A', 'B'] + F_lst )
create_pov( pin, ['E', 'F'] + F_lst )
def usecase_celestial_types():
'''
Let surface X in P^m be the blowups of P^1xP^1 in either 0 or 2 complex conjugate
points so that m=8 and m=6 respectively.
Here P^1xP^1 denotes the fiber product of the projective line with itself.
We verify for n in [3,4,5,6,7] whether X can be linearly projected into the
projective n-sphere S^n.
If m=8, then the celestial type is (2,8,n), where the first entry denotes
the number of conics contained in X through (almost) every point.
If m=6, then the celestial type is (3,6,n) or (2,6,n). If X in S^5 has celestial type
(2,6,5), then X has a real isolated singularity (see dp6_sing() for a visualization)).
'''
# We provide certificates "c_lst" and "prv_Q" for "get_surf()",
# which were obtained by a previous (long) computation.
#
# P^1xP^1
#
# We construct a parametrization of the double Segre surface dP8 in
# projective 8-space. This surface contains 2 conics through each point
#
ring = PolyRing('x,y,v,w', True)
ls_dP8 = LinearSeries(get_mon_lst([2, 2], ring.gens()), ring)
OrbTools.p('ls_dP8 =', ls_dP8)
get_surf(ls_dP8, (7 + 1, 1), [
-8, -8, -10, -6, -7, 6, 5, 6, 0, -8, -2, -7, -7, 7, -1, 0, -9, 7, 1, -9
])
prv_Q = sage_matrix([(0, 0, 0, 1, 1, 1, 0, 0, 0),
(0, 1, 0, 0, 0, 0, 0, 0, 0),
(1, 0, 1, 1, 0, 0, 0, 1, 0),
(1, 0, 0, 1, 0, 0, 1, 0, 0),
(0, 0, 0, 0, 0, 0, 1, 0, 1),
(0, 1, 0, 0, 1, 0, 1, 0, 1),
(0, 0, 0, 1, 1, 0, 1, 0, 1),
(1, 0, 0, 1, 0, 0, 1, 1, 0)])
get_surf(
ls_dP8, (6 + 1, 1),
[3, -3, 3, -7, 7, 1, -4, 3, -10, 6, -4, -6, -6, 4, -9, 3, -6, -4, 1],
prv_Q)
prv_Q = sage_matrix([(0, 1, 0, 0, 1, 0, 1, 0, 1),
(1, 1, 1, 1, 0, 1, 0, 0, 1),
(1, 1, 0, 1, 1, 1, 1, 0, 1),
(1, 1, 1, 1, 1, 1, 1, 1, 1),
(1, 0, 1, 0, 1, 0, 1, 0, 0),
(0, 0, 1, 0, 1, 0, 0, 1, 0),
(0, 0, 0, 0, 0, 0, 1, 1, 1)])
get_surf(ls_dP8, (5 + 1, 1), [
-7, -2, -1, -5, -4, 6, -2, -2, -2, 2, 9, -4, -9, -4, 2, -10, 9, -6, -1
], prv_Q)
prv_Q = sage_matrix([(0, 1, 0, 1, 1, 1, 0, 1, 1),
(1, 0, 0, 0, 1, 1, 0, 1, 1),
(1, 0, 0, 0, 1, 0, 0, 0, 1),
(0, 1, 1, 0, 0, 0, 1, 1, 0),
(1, 1, 1, 0, 0, 0, 1, 1, 0),
(0, 1, 1, 1, 0, 1, 1, 1, 0)])
get_surf(ls_dP8, (4 + 1, 1),
[-2, -3, 6, 7, -10, -2, -4, -8, -3, -4, 4, -6], prv_Q)
#
# P^1xP^1 blown up in two general complex conjugate points
#
# We construct a parametrization of a sextic del Pezzo surface dP6
# in projective 6-space, that contains 3 conics through each point.
# We show that dP6 can be projected into S^5 and S^4.
#
a0 = PolyRing('x,y,v,w', True).ext_num_field('t^2 + 1').root_gens()[0]
bp_tree = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bp_tree.add('xv', (-a0, a0), 1)
bp_tree.add('xv', (a0, -a0), 1)
ls_dP6 = LinearSeries.get([2, 2], bp_tree)
OrbTools.p('ls_dP6 =', ls_dP6)
get_surf(ls_dP6, (5 + 1, 1), [-9, -6, 1, 4, -1, -8, -5, -5, -4, 8, 1])
prv_Q = sage_matrix([(0, 0, 0, 1, 0, 1, 1), (1, 1, 0, 1, 0, 0, 0),
(0, 1, 1, 0, 1, 0, 1), (1, 1, 0, 0, 1, 0, 0),
(1, 1, 1, 1, 1, 1, 0), (1, 0, 0, 1, 0, 1, 1)])
get_surf(ls_dP6, (4 + 1, 1), [-1, -9, -10, -7, -10, -8, 0], prv_Q)
#
# P^1xP^1 blown up in two complex conjugate points that lie in the same fiber
#
# We construct a parametrization of a sextic weak del Pezzo surface wdP6
# in projective 6-space, that contains 2 conics through each point.
# We show that wdP6 can be projected into S^5 and S^4.
#
a0 = PolyRing('x,y,v,w', True).ext_num_field('t^2 + 1').root_gens()[0]
bp_tree = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bp_tree.add('xv', (a0, 0),
1) # the complex conjugate base points lie in the same fiber
bp_tree.add('xv', (-a0, 0), 1)
ls_wdP6 = LinearSeries.get([2, 2], bp_tree)
OrbTools.p('ls_wdP6 =', ls_wdP6)
get_surf(ls_wdP6, (5 + 1, 1), [-6, 8, -7, -8, 0, -8, 2, -5, -8])
prv_Q = sage_matrix([(1, 0, 0, 1, 1, 1, 0), (1, 0, 0, 1, 0, 1, 1),
(0, 1, 1, 1, 0, 1, 0), (0, 0, 0, 0, 1, 0, 0),
(0, 1, 0, 1, 1, 1, 0), (0, 0, 0, 1, 1, 1, 0)])
get_surf(ls_wdP6, (4 + 1, 1), [-2, -7, -6, -10, -2, -4, 4], prv_Q)
def ring_cyclide():
'''
Creates povray image of 4 families of circles on a ring cyclide.
'''
# We construct a trigonometric parametrization of the ring cyclide,
# by rotating a circle of radius r along a circle of radius R.
R = 2
r = 1
x, y, v, w, c0, s0, c1, s1 = sage_var('x,y,v,w,c0,s0,c1,s1')
V = sage_vector([r * c0 + R, 0, r * s0])
M = sage_matrix([(c1, -s1, 0), (s1, c1, 0), (0, 0, 1)])
pmz_AB_lst = [1] + list(M * V)
OrbTools.p('pmz_AB_lst =', pmz_AB_lst)
for pmz in pmz_AB_lst:
OrbTools.p('\t\t', sage_factor(pmz))
# convert pmz_AB_lst to rational parametrization pmz_lst
C0 = (y**2 - x**2) / (y**2 + x**2)
S0 = 2 * x * y / (y**2 + x**2)
C1 = (w**2 - v**2) / (w**2 + v**2)
S1 = 2 * v * w / (w**2 + v**2)
den = (y**2 + x**2) * (w**2 + v**2)
dct = {c0: C0, s0: S0, c1: C1, s1: S1}
pmz_lst = [den] + [(elt.subs(dct) * den).simplify_full()
for elt in list(M * V)]
OrbTools.p('pmz_lst =', pmz_lst)
# find basepoints
ls = LinearSeries(pmz_lst, PolyRing('x,y,v,w', True))
OrbTools.p(ls.get_bp_tree())
# construct linear series for families of conics
a0, a1 = PolyRing('x,y,v,w').ext_num_field('t^2+1/3').ext_num_field(
't^2+1').root_gens()
p1 = ['xv', (-a0, a1)]
p2 = ['xv', (a0, -a1)]
p3 = ['xv', (-a0, -a1)]
p4 = ['xv', (a0, a1)]
bpt_1234 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_1234.add(p1[0], p1[1], 1)
bpt_1234.add(p2[0], p2[1], 1)
bpt_1234.add(p3[0], p3[1], 1)
bpt_1234.add(p4[0], p4[1], 1)
bpt_12 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_12.add(p1[0], p1[1], 1)
bpt_12.add(p2[0], p2[1], 1)
bpt_34 = BasePointTree(['xv', 'xw', 'yv', 'yw'])
bpt_34.add(p3[0], p3[1], 1)
bpt_34.add(p4[0], p4[1], 1)
ls_22 = LinearSeries.get([2, 2], bpt_1234) # |2(l1+l2)-e1-e2-e3-e4|
ls_21 = LinearSeries.get([2, 1], bpt_1234)
ls_12 = LinearSeries.get([1, 2], bpt_1234)
ls_11a = LinearSeries.get([1, 1], bpt_12)
ls_11b = LinearSeries.get([1, 1], bpt_34)
OrbTools.p('linear series 22 =\n', ls_22)
OrbTools.p('linear series 21 =\n', ls_21)
OrbTools.p('linear series 12 =\n', ls_12)
OrbTools.p('linear series 11a =\n', ls_11a)
OrbTools.p('linear series 11b =\n', ls_11b)
# compute reparametrization
ring = PolyRing(
'x,y,v,w,c0,s0,c1,s1') # construct polynomial ring with new generators
pmz_lst = ring.coerce(pmz_lst)
x, y, v, w, c0, s0, c1, s1 = ring.gens()
X = 1 - s0
Y = c0
# see get_S1xS1_pmz()
V = 1 - s1
W = c1
q = sage_n(sage_sqrt(3)).exact_rational() # approximation of sqrt(3)
CB_dct = {x: X, y: Y, v: W * X + q * V * Y, w: V * X - q * W * Y}
DB_dct = {x: X, y: Y, v: W * X - q * V * Y, w: V * X + q * W * Y}
pmz_CB_lst = [pmz.subs(CB_dct) for pmz in pmz_lst]
pmz_DB_lst = [pmz.subs(DB_dct) for pmz in pmz_lst]
# output
OrbTools.p('pmz_AB_lst =\n', pmz_AB_lst)
OrbTools.p('pmz_CB_lst =\n', pmz_CB_lst)
OrbTools.p('pmz_DB_lst =\n', pmz_DB_lst)
# mathematica
for pmz, AB in [(pmz_AB_lst, 'AB'), (pmz_CB_lst, 'CB'),
(pmz_DB_lst, 'DB')]:
s = 'pmz' + AB + '=' + str(pmz) + ';'
s = s.replace('[', '{').replace(']', '}')
print(s)
# PovInput ring cyclide
#
pin = PovInput()
pin.path = './' + get_time_str() + '_ring_cyclide/'
pin.fname = 'orb'
pin.scale = 1
pin.cam_dct['location'] = (0, -7, 0)
pin.cam_dct['lookat'] = (0, 0, 0)
pin.cam_dct['rotate'] = (55, 0, 0) # 45
pin.shadow = True
pin.light_lst = [(0, 0, -5), (0, -5, 0), (-5, 0, 0), (0, 0, 5), (0, 5, 0),
(5, 0, 0), (-5, -5, -5), (5, -5, 5), (-5, -5, 5),
(5, -5, -5)]
pin.axes_dct['show'] = False
pin.axes_dct['len'] = 1.2
pin.width = 800
pin.height = 400
pin.quality = 11
pin.ani_delay = 10
pin.impl = None
pin.pmz_dct['A'] = (pmz_AB_lst, 0)
pin.pmz_dct['B'] = (pmz_AB_lst, 1)
pin.pmz_dct['C'] = (pmz_CB_lst, 0)
pin.pmz_dct['D'] = (pmz_DB_lst, 0)
pin.pmz_dct['FA'] = (pmz_AB_lst, 0)
pin.pmz_dct['FB'] = (pmz_AB_lst, 1)
pin.pmz_dct['FC'] = (pmz_CB_lst, 0)
pin.pmz_dct['FD'] = (pmz_DB_lst, 0)
pin.pmz_dct['WA'] = (pmz_AB_lst, 0)
pin.pmz_dct['WB'] = (pmz_AB_lst, 1)
pin.pmz_dct['WC'] = (pmz_CB_lst, 0)
pin.pmz_dct['WD'] = (pmz_DB_lst, 0)
v0_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 10)]
v1_lst = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 24)]
v1_lst_A = [
sage_pi / 2 + (sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 12)
]
v1_lstFF = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 1)]
v1_lst_WA = [
0.1, 0.52, 0.94, 1.36, 1.78, 2.2, 2.61, 3.04, 3.45, 3.88, 4.3, 4.712,
5.13, 5.55, 5.965
]
v1_lst_WB = [
0, 0.7, 1.31, 1.8, 2.18, 2.5, 2.77, 3.015, 3.26, 3.51, 3.78, 4.099,
4.49, 4.97, 5.579
]
v1_lst_WD = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 24)]
v1_lst_WC = [(sage_QQ(i) / 180) * sage_pi for i in range(0, 360, 24)]
pin.curve_dct['A'] = {
'step0': v0_lst,
'step1': v1_lst_A,
'prec': 10,
'width': 0.05
}
pin.curve_dct['B'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.05
}
pin.curve_dct['C'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.05
}
pin.curve_dct['D'] = {
'step0': v0_lst,
'step1': v1_lst,
'prec': 10,
'width': 0.05
}
pin.curve_dct['FA'] = {
'step0': v0_lst,
'step1': v1_lstFF,
'prec': 10,
'width': 0.02
}
pin.curve_dct['FB'] = {
'step0': v0_lst,
'step1': v1_lstFF,
'prec': 10,
'width': 0.02
}
pin.curve_dct['FC'] = {
'step0': v0_lst,
'step1': v1_lstFF,
'prec': 10,
'width': 0.02
}
pin.curve_dct['FD'] = {
'step0': v0_lst,
'step1': v1_lstFF,
'prec': 10,
'width': 0.02
}
pin.curve_dct['WA'] = {
'step0': v0_lst,
'step1': v1_lst_WA,
'prec': 10,
'width': 0.05
}
pin.curve_dct['WB'] = {
'step0': v0_lst,
'step1': v1_lst_WB,
'prec': 10,
'width': 0.05
}
pin.curve_dct['WC'] = {
'step0': v0_lst,
'step1': v1_lst_WC,
'prec': 10,
'width': 0.05
}
pin.curve_dct['WD'] = {
'step0': v0_lst,
'step1': v1_lst_WD,
'prec': 10,
'width': 0.05
}
# A = | rotated circle
# B = - horizontal circle
# C = / villarceau circle
# D = \ villarceau circle
col_A = rgbt2pov((28, 125, 154, 0)) # blue
col_B = rgbt2pov((74, 33, 0, 0)) # brown
col_C = rgbt2pov((75, 102, 0, 0)) # green
col_D = rgbt2pov((187, 46, 0, 0)) # red/orange
colFF = rgbt2pov((179, 200, 217, 0)) # light blue
pin.text_dct['A'] = [True, col_A, 'phong 0.2 phong_size 5']
pin.text_dct['B'] = [True, col_B, 'phong 0.2 phong_size 5']
pin.text_dct['C'] = [True, col_C, 'phong 0.2 phong_size 5']
pin.text_dct['D'] = [True, col_D, 'phong 0.2 phong_size 5']
pin.text_dct['FA'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FB'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FC'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['FD'] = [True, colFF, 'phong 0.2 phong_size 5']
pin.text_dct['WA'] = [True, col_A, 'phong 0.2 phong_size 5']
pin.text_dct['WB'] = [True, col_B, 'phong 0.2 phong_size 5']
pin.text_dct['WC'] = [True, col_C, 'phong 0.2 phong_size 5']
pin.text_dct['WD'] = [True, col_D, 'phong 0.2 phong_size 5']
# raytrace image/animation
create_pov(pin, ['A', 'C', 'D'])
create_pov(pin, ['A', 'C', 'D'] + ['FA', 'FC', 'FD'])
create_pov(pin, ['WA', 'WB', 'WC', 'WD'])
create_pov(pin, ['WA', 'WB', 'WC', 'WD'] + ['FA', 'FC', 'FD'])
create_pov(pin, ['WA', 'WB', 'WD'])
create_pov(pin, ['WA', 'WB', 'WD'] + ['FA', 'FC', 'FD'])
