How to save the plot in bitmap format with resolution 1200dpi?

I want to save the plot in the bitmap with resolution 1200dpi in MATLab. I tried but not succeeded. The program is below:

plot(x,y6);set(gca,'FontSize',12,'FontWeight','bold','LineWidth',2)
xlim([1 372])
ylabel('Temperature (deg.Cel.)','FontWeight','bold','FontSize',12)
xlabel('Months','FontWeight','bold','FontSize',12)

hold on
m1=plot(xjan,y6,'*','MarkerSize', 6,'MarkerFaceColor','black','MarkerEdgeColor', 'black');set(gca,'FontSize',12,'FontWeight','bold','LineWidth',2)
xlim([1 372])
ylabel('Temperature (deg.Cel.)','FontWeight','bold','FontSize',12)
xlabel('Months','FontWeight','bold','FontSize',12)

hold on
m2=plot(xjun,y6,'ro','MarkerSize', 4,'MarkerFaceColor','red','MarkerEdgeColor', 'red');set(gca,'FontSize',12,'FontWeight','bold','LineWidth',2)
xlim([1 372])
ylabel('Temperature (deg.Cel.)','FontWeight','bold','FontSize',12)
xlabel('Months','FontWeight','bold','FontSize',12)% hold on

leg = legend([m1 m2],{'May','August'});
title('500hPa','FontWeight','bold','FontSize',14)
%saveas(gcf,'-dpng','-r300','test.png')
print (gcf, '-dbmp','-r1200', 'myfile.bmp')

Kindly, guide me regarding this.

Thanks & Regards