Mercury fixes

[jenshnielsen]

Some small issues found while working with the code on T10

@MerlinSmiles @QCoDeS/core

[MerlinSmiles]

@jenshnielsen are you sure that your changes of [self.axes.index(ax)] to [0] actually work?
the _ATOB makes setpoint and field a len(ax) array, no?

[MerlinSmiles]

while youre at it, maybe we want to change this function:

    def _carttosphere(self, field):
        field = np.array(field)
        r = np.sqrt(np.sum(field**2))
        if r == 0:
            theta = 0
            phi = 0
        else:
            theta = np.arccos(field[2] / r)
            phi = np.arctan2(field[1],  field[0])
            if phi<0:
                phi = phi+np.pi*2
        return [r, theta, phi]

basically adding:

            if phi<0:
                phi = phi+np.pi*2

to make sure phi is always positive?

[MerlinSmiles]

and maybe we want to define if we run the magnet in current or field mode, and then remove all the ...C guys

[jenshnielsen]

@MerlinSmiles you are probably right but unfortunately it doesn't take that code path for other parameters such as z field

[MerlinSmiles]

now I see the issue, yes its only going there for the 'current' version of sending the field. Stupid mistake.

A note on the side, using the current parameters instead of tesla parameters gives you one decimal place higher in resolution on the magnet.

[jenshnielsen]

Agreed with @MerlinSmiles in Slack