This is no longer true, can’t delete so ignore.
The docs say the equation to compute the gradients is
0.5 * (circuit_plus - circuit_minus)
where circuit_plus and minus are the same circuit with the parameters shifted pi/2 (plus minus respectively). Trying to recreate this, I’ve come across a weird scaling for the sigma_x params.
Q: Is there a factor of 2 in the shift for pauli xs? i.e. is the shift ± pi instead of pi/2? If no, I can post some code that outlines this