def solve_for_sub_subspace(matrixrows, sub_sub_space,
coeffs, cvector,
iofvars, subs_rules,
fvargen, newfvars, tempgen, tempvars):
sspacedict = dict(zip(sub_sub_space, range(len(sub_sub_space))))
length = len(sub_sub_space)
augmatrixrows = []
rownumstore = [] #for debugging
for rownum, row in matrixrows.items():
if row and row[0][0] in sub_sub_space:
augmatrixrows.append(length*[0]+[cvector[rownum]])
rownumstore.append(rownum)
for el in row:
augmatrixrows[-1][sspacedict[el[0]]] = el[1]
fvars = [coeffs[ind] for ind in sub_sub_space]
augmatrix = Matrix(augmatrixrows)
oldfvars = []
if iofvars:
#ipdb.set_trace()
atoms = augmatrix.atoms(sympy.Symbol)
for iofvar in subs_rules:
if iofvar in atoms:
augmatrix = augmatrix.xreplace({iofvar: subs_rules[iofvar]})
atoms = augmatrix.atoms(sympy.Symbol)
for iofvar in iofvars:
if iofvar not in subs_rules and iofvar in atoms:
fvars.append(iofvar)
oldfvars.append(iofvar)
augmatrix = augmatrix.col_insert(-1, sympy.zeros(augmatrix.rows,1))
for row_ind in range(len(augmatrix[:,0])):
coeff_val = -sympy.expand(augmatrix[row_ind,-1]).coeff(iofvar)
augmatrix[row_ind,-2] = coeff_val
augmatrix[row_ind,-1] += coeff_val*iofvar
sols, success = linear_solve(augmatrix, fvars, iofvars, fvargen, newfvars, tempgen, tempvars, len(oldfvars))
if not success:
print(repr(augmatrix))
print(fvars)
print(rownumstore)
print(iofvars)
print(subs_rules)
raise ValueError("Failure. No solutions.")
for oldfvar in oldfvars:
if oldfvar in sols:
subs_rules.update({var: rule.xreplace({oldfvar: sols[oldfvar]})
for var, rule in subs_rules.items()})
subs_rules[oldfvar] = default_simplify(sols[oldfvar])
return sols
