The example pet_sla_and_adt.py only one eddy_contour

[ddd0203]

Hello,
When I run the pet_sla and adt.py in the examples, I can only get one eddy contour. The a_sla.effective_contour_ longitude is also a 1 * 50 ndarray. What is the reason for this? How can I solve this problem?

[AntSimi]

Take a look at #217, check matplotlib version

[ddd0203]

ok,thank you very much!