Any knows why a second line appears in the bottom x-axis?

I use this line to save (exportgraphics(fig,'RossbyFig3d.jpg','Resolution', 600)). If I use .pdf the line does not appear. By the way, I added a right axis y ticks using:

axis xy

rightytick = [190 230 290 330 350 385];

rightytick = flip(rightytick);

h2 = axes('Position', h1.Position, 'Color', 'none', 'YLim', h1.YLim, 'XLim', h1.XLim, 'XTick', [], ...

'YAxisLocation', 'right','YTick', ((1./rightytick)./86400).*1e8, 'YTickLabel', sprintf('%.0f\n', rightytick), ...

'FontSize', 10);

ylabel('Period (days)')

Do you think above caused the problem? Thank you for the help. Appreciate a lot.

[Mac]

Update:

I tried running the script without the code to plot the right y axis ticks, and the second line in the bottom x-axis is removed. Anyone knows a better way to add a right y-axis? Thanks a lot.

Answer 1

[Dyuman Joshi]

"Anyone knows a better way to add a right y-axis?"

Try yyaxis

[Mac]

Thanks Joshi. Appreciate it.