I understand that you want to remove the extra space generated in the figure.This can be achieved as follows:
[Edit] The process is explained using an example graph
Firstly,if you want to change or edit the figure properities go to property inspector:
After that go to Parent/Child section and click on Figure.
After this we will be able to see the figure properties which consists of properties like position etc.
Here we can adjust the properties to get figure area proportionate to window so that the space is optimally used.
I hope this resolves your query.
Thanks,
Venkat Siddarth V
