auto update limits of derived parameters (#166)

* call _set_automatic_limits at the start of plot to ensure derived parameters have appropriate limits even when they were defined after the creation of the NestedSamples or MCMCSamples object

* add test for auto update of derived parameters when calling plot

anesthetic/samples.py

@@ -159,6 +159,7 @@ def plot(self, ax, paramname_x, paramname_y=None, *args, **kwargs):
  Pandas array of axes objects
 
  """
+ self._set_automatic_limits()
  plot_type = kwargs.pop('plot_type', 'kde')
  do_1d_plot = paramname_y is None or paramname_x == paramname_y
  kwargs['label'] = kwargs.get('label', self.label)

tests/test_samples.py

@@ -632,6 +632,15 @@ def test_limit_assignment():
  assert ns.limits['logL'][1] == 5.748335384373301
  assert ns.limits['nlive'][0] == 1
  assert ns.limits['nlive'][1] == 125
+ # limits for derived parameters:
+ ns['x5'] = ns.x0 + ns.x1
+ assert 'x5' in ns.columns and 'x5' not in ns.limits
+ ns.plot_1d(['x5'])
+ assert 'x5' in ns.columns and 'x5' in ns.limits
+ ns['x6'] = ns.x2 + ns.x3
+ assert 'x6' in ns.columns and 'x6' not in ns.limits
+ ns.plot_2d(['x5', 'x6'])
+ assert 'x6' in ns.columns and 'x6' in ns.limits
 
 
 def test_xmin_xmax_1d():