I have obtained an x-y plot in Matlab of the sine curve and I wish to rotate this plot by 90 degrees counter clockwise. How do I do this?
In the figure you have plotted, click 'View'->'Camera Toolbar'. Use the Roll Camera icon, and that should allow you to rotate your plot.
EDIT: You can also use the camroll function to do this programatically
camroll(90)
Note, this actually rotates the camera looking at the plot clockwise, not the plot itself. So if you want to rotate the plot 90 degrees counter-clockwise, you will need to rotate the camera 90 degrees clockwise.