At least on mac ```python import vcs x=vcs.init() x.plot(s,"default","isoline","default") x.png("iso") x=vcs.init() x.plot(s,"default","isofill","default") ``` Leaves unaccessible window opened, as shown in png bellow: <img width="1104" alt="duplicate" src="https://cloud.githubusercontent.com/assets/2781425/25951228/e896edb2-3611-11e7-928a-d81007e8b94e.png">