use a new invisible figure to determine if HG2 is used, rather than gcf
use a new invisible figure to determine if HG2 is used, rather than gcf

altmany/export_fig,JacobD10/export_fig,hyiltiz/export_fig,dcherian/export_fig,qqyoungqq/export_fig,hyiltiz/export_fig,JacobD10/export_fig,dcherian/export_fig,altmany/export_fig