Please can someone help me in moving the gratings pattern randomly to left and right.The code to generate gratings pattern is given below.

n = 101
[X,Y] = meshgrid(linspace(-pi,pi,n));
sinewave2D = 8*sin(4*X);
figure(1)
imagesc(sinewave2D)
axis equal; axis off; colormap(gray);
contrast = 2;
 scaled_sinewave2D = (((contrast.*sinewave2D)+1)*127.5)+1;
image(scaled_sinewave2D)
% rescales numbers between -1 and 1 to lie between 1 and 256
colormap(gray(256))

Answer 1

[Image Analyst]

Instead of X, use X-offset where offset is the distance you want to shift the signal.

offset = 2.5; % Whatever
sinewave2D = 8 * sin(4 * (X - offset));

[Hannah Mathew]

Thanks. I don't need to shift the signal but it has to move continuously to right and left in random order.Can you help me with phase shifting in these codes?

[Image Analyst]

The general formula is

signal = amplitude * sin((2 * pi / period) * (x - phaseShift)).

So just do this:

amplitude = 8; % Whatever you want.
period = 1.5708; % Whatever you want.
% Get random number between -pi and +pi
phaseShift = 2*pi*rand(1) - pi;
signal = amplitude * sin((2 * pi / period) * (x - phaseShift));