Display a shifted grid

Hello, I would like to show the grid at a specific position using and imagesc plot.

The

grid on

is associated with thick ticks positions. I would like it to be shown at a specific position, for exeample thick tick places + offset. Rather than 1 2 3 .. it would be 1.5, 2.5 3.5 etc for example. I do not want to change the xtick axis as it is shown in the help here.

I tried the gridxy function, which has the option of the position, but it doesn't show the grid where it is not empty (I see it where I have empty data only).

Any idea ? I am using R2019a.

Cheers

Answer 1

[Star Strider]

I am not certain what you want.

Try this:

x = 1:0.1:10;                               % Create Data
y = rand(size(x));                          % Create Data

figure
imagesc(x, y, y)
grid
Ax = gca;                                   % Axis Handle
xt = Ax.XTick;                              % Get Current ‘XTick’ vector
Ax.XTick = xt + 0.5;                        % Create New ‘XTick’ Vector

.

[MaHa]

Hi,

z=rand(3,3);
figure
imagesc(z)
colormap(magma)
h=colorbar;
ylabel(h,'Z values','fontsize',20)
xlabel('x')
ylabel('y')
xlim([0.5 max(size(z,2))+0.5])
ylim([0.5 max(size(z,1))+0.5])

I would like to apply the grid for 1.5, 2.5 etc, but keeping xticks of 1, 2, 3 etc. By doing it I would improve the visibility of the plot, when I have two squares with the same color, it is hard to differentiate them.

[Star Strider]

I am still not certain what you want, and there is no ‘magma’ colormap, at least in R2020a.

That aside, try this:

z=rand(3,3);
figure
imagesc(z)
colormap(hot)
h=colorbar;
ylabel(h,'Z values','fontsize',20)
xlabel('x')
ylabel('y')
xlim([0.5 max(size(z,2))+0.5])
ylim([0.5 max(size(z,1))+0.5])
Ax = gca;                                   % Axis Handle
xt = Ax.XTick;                              % Get Current ‘XTick’ vector
Ax.XTick = min(xt):max(xt);                 % Create New ‘XTick’ Vector

.

[MaHa]

Thanks for trying ! A picture is worth a thousand words, here :

What I get if I apply grid on :

Ugly, it doesn't help at all !

What I would like :

Better grid, help to distinguish different squares.

[Star Strider]

Try this:

z=rand(3,3);
figure
imagesc(z)
yl = ylim;
xl = xlim;
gl = 0.5:3.5;                               % Grid Lines Locations
glplot = gl(2:end-1);
hold on
plot([1;1]*glplot, yl(:)*ones(size(glplot)), '-k', 'LineWidth',2)
plot(xl(:)*ones(size(glplot)), [1;1]*glplot, '-k', 'LineWidth',2)
hold off
colormap(hot)
h=colorbar;
ylabel(h,'Z values','fontsize',20)
xlabel('x')
ylabel('y')
xlim([0.5 max(size(z,2))+0.5])
ylim([0.5 max(size(z,1))+0.5])
Ax = gca;                                   % Axis Handle
xt = Ax.XTick;                              % Get Current ‘XTick’ vector
Ax.XTick = (min(xt):max(xt))+0.5;           % Create New ‘XTick’ Vector

You will obviously have to change it if the size of the ‘z’ matrix changes. If it is not square, use different ‘gl’ and ‘glplot’ vectors for the x and y direction grids.

This appears to work for this (3 x 3) grid, and should get you started.

[MaHa]

Thanks

[Star Strider]

As always, my pleasure!