maxwell's equation example can't find galgebra

[Henri Girard]

Hi,
I am new to sympy and I wanted to try it on maxwell's equations examples so I installed galgebra from git but it doesn't work ? the import is not found... ANy help ?
regards
Henri

import sys
import sympy.galgebra.GAsympy as GA
import sympy.galgebra.latex_ex as tex

GA.set_main(sys.modules[__name__])

if __name__ == '__main__':

    metric = '1  0  0  0,'+\
             '0 -1  0  0,'+\
             '0  0 -1  0,'+\
             '0  0  0 -1'

    vars = GA.make_symbols('t x y z')
    GA.MV.setup('gamma_t gamma_x gamma_y gamma_z',metric,True,vars)
    tex.Format()
    I = GA.MV(1,'pseudo')
    I.convert_to_blades()
    print ('$I$ Pseudo-Scalar')
    print ('I =',I)
    B = GA.MV('B','vector',fct=True)
    E = GA.MV('E','vector',fct=True)
    B.set_coef(1,0,0)
    E.set_coef(1,0,0)
    B *= gamma_t
    E *= gamma_t
    B.convert_to_blades()
    E.convert_to_blades()
    J = GA.MV('J','vector',fct=True)
    print ('$B$ Magnetic Field Bi-Vector')
    print ('B = Bvec gamma_0 =',B)
    print ('$E$ Electric Field Bi-Vector')
    print ('E = Evec gamma_0 =',E)
    F = E+I*B
    print ('$E+IB$ Electo-Magnetic Field Bi-Vector')
    print ('F = E+IB =',F)
    print ('$J$ Four Current')
    print ('J =',J)
    gradF = F.grad()
    gradF.convert_to_blades()
    print ('Geometric Derivative of EM Bi-Vector')
    tex.MV_format(3)
    print ('\\nabla F =',gradF)
    print ('All Maxwell Equations are')
    print ('\\nabla F = J')
    print ('Div $E$ and Curl $H$ Equations')
    print ('<\\nabla F>_1 -J =',gradF.project(1)-J,' = 0')
    print ('Curl $E$ and Div $B$ equations')
    print ('<\\nabla F>_3 =',gradF.project(3),' = 0')
    tex.xdvi(filename='Maxwell.tex')

---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-1-45c89331d82f> in <module>()
      1 import sys
----> 2 import sympy.galgebra.GAsympy as GA
      3 import sympy.galgebra.latex_ex as tex
      4 
      5 GA.set_main(sys.modules[__name__])

/home/pi/git/sage/local/lib/python2.7/site-packages/sympy/galgebra.py in <module>()
----> 1 raise ImportError("""As of SymPy 1.0 the galgebra module is maintained separately at https://github.com/brombo/galgebra""")

ImportError: As of SymPy 1.0 the galgebra module is maintained separately at https://github.com/brombo/galgebra

[Alan Bromborsky]

When you get galgebra from git in the galgebra/doc directory is galgebra.pdf.  In section 1.3 of the document are instructions of how to install galgebra including how to set the python path so that other python programs can find galgebra.

--
You received this message because you are subscribed to the Google Groups "sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscribe@googlegroups.com.
To post to this group, send email to sy...@googlegroups.com.
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/6b917548-f055-4ee6-8310-259cd0bb93f1%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Alan Bromborsky]

Here is a example of Maxwell's equation using the galgebra module from github

import sys
from sympy import symbols,sin,cos,exp,I,Matrix,simplify,Eq,S
from sympy.solvers import solve
from printer import Format,xpdf,Get_Program,Print_Function,Fmt
from ga import Ga
from metric import linear_expand

def Maxwell_in_Geom_Calculus():
    Print_Function()
    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',f=True)
    B = B.proj([g1,g2,g3])  # Make vector from spatial components of B
    print 'B =',B

    E = st4d.mv('E','vector',f=True)
    E = E.proj([g1,g2,g3])  # Make vector from spatial components of E
    print 'E =',E

    F = g0*E+i*g0*B
    print 'F =', F

    J = st4d.mv('J','vector',f=True)
    print 'J =', J

    gradF = st4d.grad*F

    print 'grad*F =', gradF.Fmt(2)

    W = gradF-J

    print 'grad*F - J = 0 =', W.Fmt(2)

    return

def dummy():
    return

def main():
    Get_Program()
    Format()

    Maxwell_in_Geom_Calculus()

    xpdf()
    return

if __name__ == "__main__":
    main()

Attached is the pdf output of the above code.