sympy consistency and add theta_i to AxionEffectiveFluid.set_params (#77

)

camb/dark_energy.py

@@ -111,10 +111,12 @@ class AxionEffectiveFluid(DarkEnergyModel):
     _fortran_class_name_ = 'TAxionEffectiveFluid'
     _fortran_class_module_ = 'DarkEnergyFluid'
 
-    def set_params(self, w_n, om, a_c):
+    def set_params(self, w_n, om, a_c, theta_i=None):
         self.w_n = w_n
         self.om = om
         self.a_c = a_c
+        if theta_i is not None:
+            self.theta_i = theta_i
 
 
 # short names for models that support w/wa

camb/symbolic.py

@@ -56,20 +56,20 @@
 
 def subs(eqs, expr):
     # generalization to act on lists of equations, and support using Eq equations.
-    # lists are substituted irrespective of order, so no RHS variables are substituted by other elements
+    # lists and dicts are substituted irrespective of order, so no RHS variables
+    # are substituted by other elements
     if isinstance(expr, (list, tuple)):
         res = [subs(eqs, ex) for ex in expr]
         return [x for x in res if x is not True]
     if not isinstance(expr, (sympy.Expr, Relational)):
         return expr
     if isinstance(eqs, dict):
-        return expr.subs(eqs)
+        return expr.subs(eqs, simultaneous=True)
     else:
         if not isinstance(eqs, (list, tuple)):
             return expr.subs(eqs.lhs, eqs.rhs)
         eqs = [(eq.lhs, eq.rhs) for eq in eqs]
-        # must use dict in order for rhs not to be substituted by subsequent lhs
-        return expr.subs(dict(eqs), simultaneous=True)
+        return expr.subs(eqs, simultaneous=True)
 
 
 def solve(eq, x):