Center of mass and total mass of a matrix

How to calculate a center of mass and total mass of 11x4 matrix?

the matrix is as follows:

a = normrnd(451,131,11,1); b = linspace(-7.67,91.83,11)'; c = linspace(-8.3,8.3,11)'; d = linspace(0,15.21,11)';

A = [a,b,c,d]

Answer 1

[Andrei Bobrov]

tot_mass = sum(A(:));
[ii,jj] = ndgrid(1:size(A,1),1:size(A,2));
R = sum(ii(:).*A(:))/tot_mass;
C = sum(jj(:).*A(:))/tot_mass;
out = [tot_mass,R,C]

[Sofiane Labane]

hi, calculate center of gravity with matlab?

Answer 2

[Image Analyst]

Two ways:

% Method 1, using mean
x = 1 : size(A, 2); % Columns.
y = 1 : size(A, 1); % Rows.
[X, Y] = meshgrid(x, y)
meanA = mean(A(:))
centerOfMassX = mean(A(:) .* X(:)) / meanA
centerOfMassY = mean(A(:) .* Y(:)) / meanA

% Method 2: using regionprops
props = regionprops(true(size(A)), A, 'WeightedCentroid')

Of course the total mass is simply sum(A(:))

totalMass = sum(A(:));

[Sofiane Labane]

Hi. How do I calculate the center of gravity with MATLAB?

[Image Analyst]

Center of gravity of what? What is that thing? Is it like a Guillatine blade? Or two rods hanging down? You need to explain.