time + freq avg doesn't work together anymore

[haavee]

Under Py2 / Numpy 1.x this worked fine:

jcli> ms xxx.ms
jcli> pt phatime; ch 0.1*last:0.9*last; avc vector; solint 30s; avt scalar;
jcli> pl

however, under python/version= 3.13.1 and numpy/2.1.3 the above sequence results in:

File ".../jiveplot/plotiterator.py", line 1761, in makePlots
rv[ self.MKLAB(fields, dl) ] = dataset_fixed(dataset.x, functional.List(chd))
                                                        ~~~~~~~~~~~~~~~^^^^^
TypeError: iteration over a 0-d array

and when we do vector averaging in time (i.s.o. scalar):

> avt vector
> pl

we get this:

'phatime' : data_quantity_time([(YTypes.phase, lambda x: numpy.ma.angle(x, True))]),
                                                         ~~~~~~~~~~~~~~^^^^^^^^^
File ".../lib/python3.13/site-packages/numpy/lib/_function_base_impl.py", line 1721, in angle
a = arctan2(zimag, zreal)
AttributeError: 'int' object has no attribute 'arctan2'