Increased tolerance for sqrt in kernels K_r2.
We had a report of numerical problems when the tolerance was 1e-40. So in GPflow 1 it got changed to 1e-36, but this wasn't ported to GPflow 2, hence why we're fixing it now.
@@ -77,7 +77,7 @@ class IsotropicStationary(Stationary):
def K_r2(self, r2):
if hasattr(self, "K_r"):
# Clipping around the (single) float precision which is ~1e-45.
- r = tf.sqrt(tf.maximum(r2, 1e-40))
+ r = tf.sqrt(tf.maximum(r2, 1e-36))
return self.K_r(r) # pylint: disable=no-member
raise NotImplementedError
