calc_ramp and add_ramp incorrect usage of max_grad and max_slew?

[turbotage]

Describe the bug

calc_ramp specifies that you can give max_grad and slew_rate as a [3,1] array, but inside the function, max_grad and slew_rate is set as

if np.all(np.where(max_grad <= 0)):
    max_grad = [system.max_grad]
if np.all(np.where(max_slew <= 0)):
    max_slew = [system.max_slew]

But if max_grad is an array this won't work since (same for max_slew)

>>> max_grad = np.ones((3,1))
>>> np.all(np.where(max_grad <= 0))
True

Also, for add_ramp, the docs specifies that max_grad and max_slew should be ints? This seems strange since they are floats everywhere else. Also, for add_ramps the option to use max_grad and max_slew for each gradient axis is not an option as it is for calc_ramps?

This whole thing made me think about what max_grad and max_slew means in the system settings? The most reasonable thing is that they denote the max_grad and max_slew every gradient channel can produce right? But if this is the case, passing just this number to add_ramps does not make sense either because then you end up here in calc_ramps

if mode == 0:
  if np.linalg.norm(G0) > max_grad or np.linalg.norm(G_end) > max_grad:
      break
  success, k_out = __joinleft0(
      k0=k0, k_end=k_end, G0=G0, G_end=G_end, use_points=use_points
  )

And if each gradient channel are close to, but still smaller than max_grad then np.linalg.norm(G0) > max_grad or np.linalg.norm(G_end) > max_grad: will still evaluate to true

Expected behavior I either expect the ramp functions to ignore per channel max_grad and max_slew and just take these as numbers and assume they are all the same for each axis. Or properly handle the per axis behaviour. Also I expect max_grad and max_slew should be given as a float as everywhere else

• OS: Ubuntu
• OS Version: 24.04
• pypulseq version: 1.4.2