How to set the default corner for origo in imagesc?

I would like to use origo in the bottom-left corner as mathematicians used to.

[Mr M.]

The answer is: set(gca,'YDir','normal');

[Jason Stockton]

Thank you for posting the answer!

Answer 1

[Geoff Hayes]

Merse - do you just want to reverse the order of the y-axis so that zero (along y) is in the bottom left corner? Or do you want to be able to manipulate the data in the image given that new ordering? If just the former, then you could do

 % get the handle to the image
 hImg = imagesc(...);

 % get the handle to the parent axes
 hAxs = get(hImg,'Parent');

 % reverse the order of the y-axis tick labels
 yAxisTickLabels = get(hAxs, 'YTickLabel');
 set(hAxs,'YTickLabel',flipud(yAxisTickLabels));

The above code just flips the y-axis tick labels so that their order is reversed. NOTE that this does not change the manner in which you can access the data in the image, all it does is flip the labels.

[Mr M.]

I would like to flip the picture also.

[Geoff Hayes]

See flipud which will allow you to flip your image.

Answer 2

[Image Analyst]

By default, images use

axis ij

which puts the (1,1) location at the upper left as is the convention for arrays and images. If you want it at the lower left, like an (x,y) plot use

axis xy;

[Giammarco Nalin]

where should I put this modifcation?

[Image Analyst]

After you call plot(), image(), imshow(), or imagesc().

[Louis]

thank you, you are a boss