# Revision history [back]

Sorry for the update - believe it or not, after years this was finally implemented (as a method, not function) in Trac 3021.

sage: var('y z')
(y, z)
sage: V = vector([x^2*y, z, 3*y^2])sage: V.curl([x,y,z]) # necessary since otherwise why should x be first?(6*y - 1, 0, -x^2)
sage: V.div()  # same reason
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<snip>
ValueError: Unable to determine ordered variable names for Symbolic Ring
sage: V.div([x,y,z])
2*x*y


Sorry for the update - believe it or not, after years this was finally implemented (as a method, not function) in Trac 3021.

sage: var('y z')
(y, z)
sage: V = vector([x^2*y, z, 3*y^2])sage: V.curl([x,y,z]) # necessary since otherwise why should x be first?(6*y first?
(6*y - 1, 0, -x^2)
sage: V.div()  # same reason
---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
<snip>
ValueError: Unable to determine ordered variable names for Symbolic Ring
sage: V.div([x,y,z])
2*x*y