Question

What are the default dimensions of graphics window

Answer 1

Explanation:

Window layout/Windows Size

For more information, see IDL Preferences. Alternatively, you can specify that graphics windows have a default width and height of half the screen width and height by checking the 1/4 Screen Size checkbox

Answer 2

Alternatively, you can specify that graphics windows have a default width and height of half the screen width and height by checking the 1/4 Screen Size checkbox.

Hope you get the correct answer.