Structure function failing

Hey,

Sometimes the structure function fails, with the below error. Not quite sure if/how to fix it but wondered if otherwise it could just be optional to fit the structure function or something?

Thanks

/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py:125: RuntimeWarning: divide by zero encountered in log10
  par = np.linalg.lstsq( A.T, np.log10(variance[myselect][~mask]) )[0]
/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py:125: FutureWarning: `rcond` parameter will change to the default of machine precision times ``max(M, N)`` where M a
nd N are the input matrix dimensions.
To use the future default and silence this warning we advise to pass `rcond=None`, to keep using the old, explicitly pass `rcond=-1`.
  par = np.linalg.lstsq( A.T, np.log10(variance[myselect][~mask]) )[0]
/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py:165: UserWarning: Attempted to set non-positive bottom ylim on a log-scaled axis.
Invalid limit will be ignored.
  ax.set_ylim(ymin,ymax)
/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py:166: RuntimeWarning: divide by zero encountered in log10
  ax1.set_ylim(np.log10(ymin),np.log10(ymax))
Traceback (most recent call last):
  File "/usr/local/bin/losoto", line 154, in <module>
    returncode += ops[ op ]._run_parser( soltab, parser, step )
  File "/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py", line 16, in _run_parser
    return run(soltab, doUnwrap, refAnt, plotName, ndiv)
  File "/usr/local/lib/python3.8/dist-packages/losoto/operations/structure.py", line 166, in run
    ax1.set_ylim(np.log10(ymin),np.log10(ymax))
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/axes/_base.py", line 4027, in set_ylim
    bottom = self._validate_converted_limits(bottom, self.convert_yunits)
  File "/usr/local/lib/python3.8/dist-packages/matplotlib/axes/_base.py", line 3614, in _validate_converted_limits
    raise ValueError("Axis limits cannot be NaN or Inf")
ValueError: Axis limits cannot be NaN or Inf