How do I edit the axes of an image in MATLAB to reverse the direction?

NLed picture NLed · May 19, 2010 · Viewed 19.6k times · Source

I would like to edit the axes in my series of images being displayed.

This is what my image looks like:

parabola

As you can see, it ranges from 0 to about 500 from top to bottom. Can I invert that? Plus, I want to mirror the image being shown, so that it starts from left to right... or, if it's possible, to let the axes show from right to left.

Answer

gnovice picture gnovice · May 19, 2010

To reverse an axis, you can set the 'XDir' or 'YDir' property of the current axes to 'reverse':

set(gca,'XDir','reverse');  %# This flips the x axis

Keep in mind that flipping an axis in this way flips everything in the plot as well. This probably isn't what you want to do for the y axis. You probably just want to flip the y axis labels, which you can do by modifying the 'YTickLabel' property in the following way:

yLimits = get(gca,'YLim');  %# Get the y axis limits
yTicks = yLimits(2)-get(gca,'YTick');  %# Get the y axis tick values and
                                       %#   subtract them from the upper limit
set(gca,'YTickLabel',num2str(yTicks.'));  %'# Convert the tick values to strings
                                           %#   and update the y axis labels