What is the meaning of symbol “.”in this code

I was watching a tutorial today on graphics, and one line of code went like this.

x = linspace(0,3); y = x.^2.*sin(x); plot(x,y);

What does the sign "."? Does it have any specific meaning?

Thank you all.

Answer 1

[Jan]

While ^ is the power operation, which acts on the complete array, .^ is the elementwise power. For a scalar, this is no difference:

a = 17;
a ^ 2   % 289, same as a * a
a .^ 2  % 289, same as a * a

a = [2, 3];
a ^ 2   % ERROR, same as [2, 3] * [2, 3] - this is not defined
a .^ 2  % [4, 9], same as [2^2, 3^2]
        % And equivalent to: a .* a

The power operator ^ is defined for square matrices only.

The same for .* : * multiples the arrays, while .* operates on the array elements.

Answer 2

[Arif Hoq]

It's element wise operation. you can read this

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html

https://www.mathworks.com/help/matlab/ref/times.html