Rand Function in MATLAB

I am very new to MATLAB. I'm trying to create trials using the rand function. I want four different rectangles on my figure to highlight at random.

Below is my code.

The figure is plotted with four rectangles, I want to highlight the four rectangles on random. Thanks!

%Create the figure for trial 
t = figure
xlim([1 5])
ylim([1 5])
lower_l=rectangle('Position', [1.5 1.5 .5 .5]); 
hold on
upper_l=rectangle('Position', [1.5 4 .5 .5]);
hold on
lower_r=rectangle('Position', [4 1.5 .5 .5]);
hold on
upper_r=rectangle('Position', [4 4 .5 .5]);
hold on 
cross=text(3, 3, '+');
set(cross, 'fontsize', 20);**

  
%create condition without target 
y = rand(lower_l, lower_r, upper_l, upper_r);
set(y, 'EdgeColor', 'r')
pause(0.1)
set(y, 'EdgeColor', 'k')
pause(0.3)

Appreciate any comments!

Answer 1

[Cris LaPierre]

The random functions in MATLAB generate random numbers, not select a random value from a supplied vector.

What you could consider doing is creating a vector of the rectangle handles, and then randomly generate an index to extract one of them. That might look somethign like this

%create condition without target 
y = [lower_l, lower_r, upper_l, upper_r];
idx = randi(length(y));

set(y(idx), 'EdgeColor', 'r')
pause(0.1)
set(y(idx), 'EdgeColor', 'k')
pause(0.3)

[Aashita Galundia]

Thanks, this was very helful!