def VectorComponents(X, basis):
    (coefs, bases) = linear_expand(X.obj)
    cdict = {}
    for (coef, base) in zip(coefs, bases):
        cdict[str(base)] = coef
    comp = []
    for base in basis:
        if base in cdict:
            comp.append(cdict[base])
        else:
            comp.append(0)
    return comp
Example #2
0
def VectorComponents(X, basis):
    (coefs, bases) = linear_expand(X.obj)
    cdict = {}
    for (coef, base) in zip(coefs, bases):
        cdict[str(base)] = coef
    comp = []
    for base in basis:
        if base in cdict:
            comp.append(cdict[base])
        else:
            comp.append(0)
    return comp
    def __init__(self, x, coords, debug=False, I=None):
        """
        coords: list of coordinate variables
        x: vector fuction of coordinate variables (parametric surface)
        """
        self.I = I
        self.x = x
        self.coords = coords

        self.basis = []
        self.basis_str = []
        self.embedded_basis = []
        for u in coords:
            tv = x.diff(u)
            self.basis.append(tv)
            (coefs, bases) = linear_expand(tv.obj)
            tc = {}
            for (coef, base) in zip(coefs, bases):
                str_base = str(base)
                tc[str_base] = coef
                if str_base not in self.embedded_basis:
                    self.embedded_basis.append(str_base)
            self.basis_str.append(tc)

        self.gij = []

        for base1 in self.basis:
            tmp = []
            for base2 in self.basis:
                tmp.append(simplify(trigsimp((base1 | base2).scalar())))
            self.gij.append(tmp)

        for tv in self.basis_str:
            for base in self.embedded_basis:
                if base not in tv:
                    tv[base] = 0

        self.dim = len(self.basis)

        indexes = tuple(range(self.dim))
        self.index = [()]
        for i in indexes:
            self.index.append(tuple(combinations(indexes, i + 1)))
        self.index = tuple(self.index)

        self.MFbasis = [[MV.ONE], self.basis]

        for igrade in self.index[2:]:
            grade = []
            for iblade in igrade:
                blade = MV(1, 'scalar')
                for ibasis in iblade:
                    blade ^= self.basis[ibasis]
                blade = blade.trigsimp(deep=True, recursive=True)
                grade.append(blade)
            self.MFbasis.append(grade)
        self.E = self.MFbasis[-1][0]
        self.E_sq = trigsimp((self.E * self.E).scalar(),
                             deep=True,
                             recursive=True)

        duals = copy.copy(self.MFbasis[-2])

        duals.reverse()
        sgn = 1
        self.rbasis = []
        for dual in duals:
            recpv = (sgn * dual * self.E).trigsimp(deep=True, recursive=True)
            self.rbasis.append(recpv)
            sgn = -sgn

        self.dbasis = []

        for base in self.basis:
            dbase = []
            for coord in self.coords:
                d = base.diff(coord).trigsimp(deep=True, recursive=True)
                dbase.append(d)
            self.dbasis.append(dbase)

        self.surface = {}
        (coefs, bases) = linear_expand(self.x.obj)

        for (coef, base) in zip(coefs, bases):
            self.surface[str(base)] = coef

        self.grad = MV()
        self.grad.is_grad = True
        self.grad.blade_rep = True
        self.grad.igrade = 1
        self.grad.rcpr_bases_MV = []
        for rbase in self.rbasis:
            self.grad.rcpr_bases_MV.append(rbase / self.E_sq)
        self.grad.rcpr_bases_MV = tuple(self.grad.rcpr_bases_MV)
        self.grad.coords = self.coords
        self.grad.norm = self.E_sq
        self.grad.connection = {}

        if debug:
            oprint('x', self.x, 'coords', self.coords, 'basis vectors',
                   self.basis, 'index', self.index, 'basis blades',
                   self.MFbasis, 'E', self.E, 'E**2', self.E_sq, '*basis',
                   duals, 'rbasis', self.rbasis, 'basis derivatives',
                   self.dbasis, 'surface', self.surface, 'basis strings',
                   self.basis_str, 'embedding basis', self.embedded_basis,
                   'metric tensor', self.gij)
Example #4
0
    def __init__(self, x, coords, debug=False, I=None):
        """
        coords: list of coordinate variables
        x: vector fuction of coordinate variables (parametric surface)
        """
        self.I = I
        self.x = x
        self.coords = coords

        self.basis = []
        self.basis_str = []
        self.embedded_basis = []
        for u in coords:
            tv = x.diff(u)
            self.basis.append(tv)
            (coefs, bases) = linear_expand(tv.obj)
            tc = {}
            for (coef, base) in zip(coefs, bases):
                str_base = str(base)
                tc[str_base] = coef
                if str_base not in self.embedded_basis:
                    self.embedded_basis.append(str_base)
            self.basis_str.append(tc)

        self.gij = []

        for base1 in self.basis:
            tmp = []
            for base2 in self.basis:
                tmp.append(simplify(trigsimp((base1 | base2).scalar())))
            self.gij.append(tmp)

        for tv in self.basis_str:
            for base in self.embedded_basis:
                if base not in tv:
                    tv[base] = 0

        self.dim = len(self.basis)

        indexes = tuple(range(self.dim))
        self.index = [()]
        for i in indexes:
            self.index.append(tuple(combinations(indexes, i + 1)))
        self.index = tuple(self.index)

        self.MFbasis = [[MV.ONE], self.basis]

        for igrade in self.index[2:]:
            grade = []
            for iblade in igrade:
                blade = MV(1, 'scalar')
                for ibasis in iblade:
                    blade ^= self.basis[ibasis]
                blade = blade.trigsimp(deep=True, recursive=True)
                grade.append(blade)
            self.MFbasis.append(grade)
        self.E = self.MFbasis[-1][0]
        self.E_sq = trigsimp((self.E * self.E).scalar(), deep=True, recursive=True)

        duals = copy.copy(self.MFbasis[-2])

        duals.reverse()
        sgn = 1
        self.rbasis = []
        for dual in duals:
            recpv = (sgn * dual * self.E).trigsimp(deep=True, recursive=True)
            self.rbasis.append(recpv)
            sgn = -sgn

        self.dbasis = []

        for base in self.basis:
            dbase = []
            for coord in self.coords:
                d = base.diff(coord).trigsimp(deep=True, recursive=True)
                dbase.append(d)
            self.dbasis.append(dbase)

        self.surface = {}
        (coefs, bases) = linear_expand(self.x.obj)

        for (coef, base) in zip(coefs, bases):
            self.surface[str(base)] = coef

        self.grad = MV()
        self.grad.is_grad = True
        self.grad.blade_rep = True
        self.grad.igrade = 1
        self.grad.rcpr_bases_MV = []
        for rbase in self.rbasis:
            self.grad.rcpr_bases_MV.append(rbase / self.E_sq)
        self.grad.rcpr_bases_MV = tuple(self.grad.rcpr_bases_MV)
        self.grad.coords = self.coords
        self.grad.norm = self.E_sq
        self.grad.connection = {}

        if debug:
            oprint('x', self.x,
                   'coords', self.coords,
                   'basis vectors', self.basis,
                   'index', self.index,
                   'basis blades', self.MFbasis,
                   'E', self.E,
                   'E**2', self.E_sq,
                   '*basis', duals,
                   'rbasis', self.rbasis,
                   'basis derivatives', self.dbasis,
                   'surface', self.surface,
                   'basis strings', self.basis_str,
                   'embedding basis', self.embedded_basis,
                   'metric tensor', self.gij)