Function: mfisetaquo
Section: modular_forms
C-Name: mfisetaquo
Prototype: GD0,L,
Help: mfisetaquo(f,{flag=0}): if the generalized modular form f
 is a holomorphic eta quotient, return the eta quotient matrix, else return 0.
 If flag is set, also accept meromorphic eta quotients.
Doc: if the generalized modular form $f$ is a holomorphic eta quotient,
 return the eta quotient matrix, else return 0. If \fl is set, also accept
 meromorphic eta quotients: check whether $f = q^{-v(g)} g(q)$ for some
 eta quotient $g$; if so, return the eta quotient matrix attached to $g$,
 else return $0$.
 See \kbd{mffrometaquo}.

 \bprog
 ? mfisetaquo(mfDelta())
 %1 =
 [1 24]
 ? f = mffrometaquo([1,1;23,1]);
 ? mfisetaquo(f)
 %3 =
 [ 1 1]

 [23 1]
 ? f = mffrometaquo([1,-24], 1);
 ? mfisetaquo(f) \\ nonholomorphic
 %5 = 0
 ? mfisetaquo(f,1)
 %6 =
 [1 -24]
 @eprog
