explain [r c]=size(trial_03) in matlab

size() is a built-in MATLAB function that returns the size of a matrix. In the case of trial_03, which is assumed to be a matrix, [r c] = size(trial_03) would return two values, r and c, corresponding to the number of rows and columns in the trial_03 matrix, respectively. This is an example of MATLAB's multiple output assignment syntax, which allows multiple variables to be assigned values simultaneously.