Search code examples
matlabrotationmatlab-figureaxes

How to rotate image and axes together on Matlab?

Code 1 where flipping vertically and/or horizontally does not affect axes(); Code 2 where proposed solution does not yield the expected output

close all; clear all; clc;
x = [5 8];
y = [3 6];
C = [0 2 4 6; 8 10 12 14; 16 18 20 22];
C2 = C(:,end:-1:1,:);           %# horizontal flip
C3 = C(end:-1:1,:,:);           %# vertical flip
C4 = C(end:-1:1,end:-1:1,:);    %# horizontal+vertical flip

% https://stackoverflow.com/a/4010203/54964
subplot(2,2,1), imagesc(x,y,C)
subplot(2,2,2), imagesc(x,y,C2)
subplot(2,2,3), imagesc(x,y,C3)
subplot(2,2,4), imagesc(x,y,C4)

%% Rotations of axes() unsuccessfully 
% https://stackoverflow.com/a/15071734/54964
figure
subplot(2,2,1), imagesc(x,y,C)
x = linspace(1, size(C, 2), numel(x)); % reverse only x
set(gca, 'XTick', x, 'XTickLabel', x)
subplot(2,2,2), imagesc(x,y,C2)

x = linspace(1, size(C, 2), numel(x)); % reverse back x
set(gca, 'XTick', x, 'XTickLabel', x)  % reverse y
y = linspace(1, size(C, 1), numel(y));
set(gca, 'YTick', y, 'YTickLabel', flipud(y(:)))
subplot(2,2,3), imagesc(x,y,C3)

x = linspace(1, size(C, 2), numel(x)); % now both x,y reversed
set(gca, 'XTick', x, 'XTickLabel', x)
subplot(2,2,4), imagesc(x,y,C4)

Fig. 1 Output where axis stay untouched but images are flipped correctly, Fig. 2 Output from attempt with moving xticks/yticks

enter image description here enter image description here

Expected output:

  • Fig.1 (top-left) all correct in axes with figure
  • Fig.2 (top-right) y-axis correct but x-axis from 8 to 5
  • Fig.3 (lower-left) y-axis from 6 to 3 but x-axis correct
  • Fig.4 (lower-right) y-axis correct but x-axis from 3 to 6

Attempt 2

Code 

% 1 start of vector 2 end of vector 3 length of vector 
figure
subplot(2,2,1), imagesc(x,y,C)
x = linspace(size(C, 2), 1, numel(x)); % reverse only x
set(gca, 'XTick', x, 'XTickLabel', x)
subplot(2,2,2), imagesc(x,y,C2)

x = linspace(1, size(C, 2), numel(x)); % reverse back x
set(gca, 'XTick', x, 'XTickLabel', x)  
y = linspace(size(C, 1), 1, numel(y)); % reverse y
set(gca, 'YTick', y, 'YTickLabel', flipud(y(:)))
subplot(2,2,3), imagesc(x,y,C3)

x = linspace(size(C, 2), 1, numel(x)); % now both x,y reversed
set(gca, 'XTick', x, 'XTickLabel', x)
y = linspace(1, size(C, 1), numel(y)); % reverse y
set(gca, 'YTick', y, 'YTickLabel', flipud(y(:)))
subplot(2,2,4), imagesc(x,y,C4)

Output

Error using matlab.graphics.axis.Axes/set
While setting the 'XTick' property of 'Axes':
Value must be a vector of type single or double whose values increase

Error in test_imagesc_subplot_figure (line 26)
set(gca, 'XTick', x, 'XTickLabel', x)

Eskapp's proposal

I do unsuccessfully the following but no change on Fig. 2; the first row of figures stay in the same increasing order of xaxis; I also tried instead of reverse - normal

figure
subplot(2,2,1), imagesc(x,y,C)
x = linspace(1, size(C, 2), numel(x)); % reverse only x
set(gca,'xdir','reverse')
subplot(2,2,2), imagesc(x,y,C2)

  • Output of Fig. 1 and Fig. 2 axis stay the same

    enter image description here

Studying EBH's answer

Output in the y-axis label when using set(gca,'XTick',x,'XTickLabel',x, 'YTick',y,'YTickLabel',fliplr(y)) with variables y=linspace(0,180,181); x=0:0.5:10

enter image description here

Matlab: 2016a
OS: Debian 8.5 64 bit
Hardware: Asus Zenbook UX303UA

Solution

  • If I correctly understand your question, then this code does what you look for:

    x = 5:8;
y = 3:6;
C = reshape(0:2:22,4,3).';
C2 = fliplr(C); % horizontal flip
C3 = flipud(C); % vertical flip
C4 = rot90(C,2); % horizontal+vertical flip

% the answer starts here:
subplot(2,2,1), imagesc(x,y,C)
set(gca,'XTick',x,'XTickLabel',x,...
     'YTick',y,'YTickLabel',y)
subplot(2,2,2), imagesc(x,y,C2)
set(gca,'XTick',x,'XTickLabel',fliplr(x),...
     'YTick',y,'YTickLabel',y)
subplot(2,2,3), imagesc(x,y,C3)
set(gca,'XTick',x,'XTickLabel',x,...
     'YTick',y,'YTickLabel',fliplr(y))
subplot(2,2,4), imagesc(x,y,C4)
set(gca,'XTick',x,'XTickLabel',fliplr(x),...
     'YTick',y,'YTickLabel',fliplr(y))

    the result:

    rot_axes

    I changed you x and y from 2-element vectors, but it works also if:

    x = [5 8];
y = [3 6];

    BTW...

    Instead of manipulating C and create C2...C4, you can just write:

    subplot 221, imagesc(x,y,C)
subplot 222, imagesc(fliplr(x),y,C)
subplot 223, imagesc(x,fliplr(y),C)
subplot 224, imagesc(fliplr(x),fliplr(y),C)

    and add the manipulation on the axis after each call to subplot like before.

    Edit:

    Using your sizes and limits of the vectors:

    x = linspace(0,10,6);
y = linspace(0,180,19); % no need to plot each label
N = 3613;
C = diag(1:N)*ones(N)+rot90(diag(1:N)*ones(N)); % some arbitrary matrix

    where all the rest of the code above remains the same, I get the following result:

    rot_ax2