How can I get more divisions in x- and y- axes scaling when plotting with imagesc to have a clear picture and introduce the proper scaling along x- & y- axes?

clc;

[x,y] = meshgrid(linspace(-0.6, 0.6), linspace(-0.6, 0.6));

[phi,r] = cart2pol(x,y);

% Omega_r -vortex beam specification

l = 2;

p = 2;

w0 = 0.2;

R = sqrt(2).*r./w0;

RR = r./w0;

Omega01 = exp(-RR.^2);

Lpl = 0;

for m = 0:p;

Lpl = Lpl + (((-1).^m)./factorial(m)).*nchoosek(p+l,p-m).*(R.^(2.*m));

end;

Omega_r = Omega01.*(RR.^(abs(l))).*Lpl.*exp(-i.*l.*phi);

figure;

imagesc(angle(Omega_r));

colormap jet

colorbar

[Pradipta Panchadhyayee]

Thanks a lot. It works perfectly.

Answer 1

[Mathieu NOE]

hello

simply specify the number of points when you call linspace

here I introduced N = 500 (N = 100 by default)

N = 500;
[x,y] = meshgrid(linspace(-0.6, 0.6 ,N), linspace(-0.6, 0.6 ,N));
[phi,r] = cart2pol(x,y);
% Omega_r -vortex beam specification
l = 2;
p = 2;
w0 = 0.2;
R = sqrt(2).*r./w0;
RR = r./w0;
Omega01 = exp(-RR.^2);
Lpl = 0;
for m = 0:p
    Lpl = Lpl + (((-1).^m)./factorial(m)).*nchoosek(p+l,p-m).*(R.^(2.*m));
end
Omega_r = Omega01.*(RR.^(abs(l))).*Lpl.*exp(-1i.*l.*phi);
figure;
imagesc(angle(Omega_r));
colormap jet
colorbar
axis square

[Pradipta Panchadhyayee]

Thanks for your response. I had this kind of plot by inserting the option of number of divisions. But I was unable to change the x-axis and y-axis scalings (-0.6 to 0.6). Still this problem persists. This is not resolved.

[Mathieu NOE]

try this

you need to create x and y vectors (before the meshgrid call) - that will be used latter as arguments to pass to imagesc

now your axes are displayed with -0.6 / + 0.6 range

N = 500;
x = linspace(-0.6, 0.6 ,N);
y = linspace(-0.6, 0.6 ,N);
[X,Y] = meshgrid(x,y);
[phi,r] = cart2pol(X,Y);
% Omega_r -vortex beam specification
l = 2;
p = 2;
w0 = 0.2;
R = sqrt(2).*r./w0;
RR = r./w0;
Omega01 = exp(-RR.^2);
Lpl = 0;
for m = 0:p
    Lpl = Lpl + (((-1).^m)./factorial(m)).*nchoosek(p+l,p-m).*(R.^(2.*m));
end
Omega_r = Omega01.*(RR.^(abs(l))).*Lpl.*exp(-1i.*l.*phi);
figure;
imagesc(x,y,angle(Omega_r));
colormap jet
colorbar
axis square