pygae/galgebra

import sys
from sympy import symbols, exp, I, Matrix, solve, simplify
from galgebra.printer import Format, xpdf, Print_Function
from galgebra.ga import Ga
from galgebra.metric import linear_expand

Format()
X = (t, x, y, z) = symbols('t x y z', real=True)
(st4d, g0, g1, g2, g3) = Ga.build('gamma*t|x|y|z', g=[1, -1, -1, -1], coords=X)

i = st4d.i

B = st4d.mv('B', 'vector')
E = st4d.mv('E', 'vector')
B.set_coef(1, 0, 0)
E.set_coef(1, 0, 0)
B *= g0
E *= g0
F = E + i * B

kx, ky, kz, w = symbols('k_x k_y k_z omega', real=True)
kv = kx * g1 + ky * g2 + kz * g3
xv = x * g1 + y * g2 + z * g3
KX = ((w * g0 + kv) | (t * g0 + xv)).scalar()

Ixyz = g1 * g2 * g3

F = F * exp(I * KX)

print(r'\text{Pseudo Scalar\;\;}I =', i)
print(r'%I_{xyz} =', Ixyz)
print(F.Fmt(3, '\\text{Electromagnetic Field Bi-Vector\\;\\;} F'))
gradF = st4d.grad * F

print('#Geom Derivative of Electomagnetic Field Bi-Vector')
print(gradF.Fmt(3, 'grad*F = 0'))

gradF = gradF /  (I * exp(I * KX))
print(gradF.Fmt(3, r'%\lp\bm{\nabla}F\rp /\lp i e^{iK\cdot X}\rp = 0'))

g = '1 # 0 0,# 1 0 0,0 0 1 0,0 0 0 -1'
X = (xE, xB, xk, t) = symbols('x_E x_B x_k t', real=True)
(EBkst, eE, eB, ek, et) = Ga.build('e_E e_B e_k t', g=g, coords=X)

i = EBkst.i

E, B, k, w = symbols('E B k omega', real=True)

F = E * eE * et + i * B * eB * et
kv = k * ek + w * et
xv = xE * eE + xB * eB + xk * ek + t * et
KX = (kv | xv).scalar()
F = F * exp(I * KX)

print(r'%\mbox{set } e_{E}\cdot e_{k} = e_{B}\cdot e_{k} = 0' +
      r'\mbox{ and } e_{E}\cdot e_{E} = e_{B}\cdot e_{B} = ' +
      r'e_{k}\cdot e_{k} = -e_{t}\cdot e_{t} = 1')

print('g =', EBkst.g)

print('K|X =', KX)
print('F =', F)
(EBkst.grad * F).Fmt(3, 'grad*F = 0')

gradF_reduced = (EBkst.grad * F) /  (I * exp(I * KX))

print(gradF_reduced.Fmt(3, r'%\lp\bm{\nabla}F\rp/\lp ie^{iK\cdot X} \rp = 0'))

print(r'%\mbox{Previous equation requires that: }e_{E}\cdot e_{B} = 0' +
      r'\mbox{ if }B\ne 0\mbox{ and }k\ne 0')

gradF_reduced = gradF_reduced.subs({EBkst.g[0, 1]: 0})
print(gradF_reduced.Fmt(3, r'%\lp\bm{\nabla}F\rp/\lp ie^{iK\cdot X} \rp = 0'))

(coefs, bases) = linear_expand(gradF_reduced.obj)

eq1 = coefs[0]
eq2 = coefs[1]

B1 = solve(eq1, B)[0]
B2 = solve(eq2, B)[0]

print(r'\mbox{eq1: }B =', B1)
print(r'\mbox{eq2: }B =', B2)

eq3 = B1 - B2

print(r'\mbox{eq3 = eq1-eq2: }0 =', eq3)
eq3 = simplify(eq3 /  E)
print(r'\mbox{eq3 = (eq1-eq2)/E: }0 =', eq3)
print(r'#Solutions for $k$ and $B$ in terms of $\omega$ and $E$:')
print('k =', Matrix(solve(eq3, k)))
print('B =', Matrix([B1.subs(w, k), B1.subs(-w, k)]))
xpdf(paper='landscape', prog=True)