Problem when plotting a matrix

When I use the 'imagesc' function to plot the image with scaled colors, the value on the y coordinate always goes from the min to max from top to bottom, which makes the figure very weird..

I want the y axis to start from 0 to 1, as we usually labelled it..

But even if I get the bottom half and inverse the sequence in my 'Y'(so it goes from 0 to 1), but when plotted, it will again always label it from the min to max from top to bottom... is there any ways I can fix it?

f1 = figure;
imagesc(X,Y,abs(log(Z1shift)));
colorbar;
title('Dispersion M_x');
xlabel('k_x', 'FontSize', 30);
ylabel('f/Hz','FontSize', 30);
set(gca, 'FontSize', 20);
saveas(f1, [sname 'Mx'], 'png');

Answer 1

[Agnish Dutta]

From what I understand, you want to plot the values of 'abs(log(Z1shift))' matrix in a particular range.

imagesc(x,y,C) specifies the image location. Use x and y to specify the locations of the corners corresponding to C(1,1) and C(m,n). To specify both corners, set x and y as two-element vectors. To specify the first corner and let imagesc determine the other, set x and y as scalar values. The image is stretched and oriented as applicable.

Refer to the following link for more information:

https://www.mathworks.com/help/matlab/ref/imagesc.html#buxkjup-2

[Yixin Shao]

I know, but usually, when you plot something, you what the value increase from origin in y-axis, but when you use imagesc, no matter how you set the "Y", the value will always be adjusted to go from small to large from top to bottom(as I showed, from -1 to 1), which is usually not what we want.