initialize growth
@@ -1222,6 +1222,10 @@ class CosmologyCalculator(Cosmology):
raise ValueError("`pk_linear` must contain keys 'a', 'k' "
"and 'delta_matter:delta_matter' "
"(at least)")
+
+ # needed for high-z extrapolation
+ self.compute_growth()
+
na = len(pk_linear['a'])
nk = len(pk_linear['k'])
lk = np.log(pk_linear['k'])
