Hi 雪明 邓,
I understand that you're looking for an explanation of the numerical values in the variables “r1” and “c1” produced by your MATLAB code. The values in “r1” represent the row indices and the values in “c1” represent the column indices of elements in matrices “X” and “Y” that meet the specified conditions: “X” is less than or equal to “Y”, ”Y” is positive and less than or equal to 400, and “X” is positive.
In essence, “r1” and “c1” tell you the positions of the points in the grid formed by “meshgrid” where the conditions are true.
For more information on “find” function, refer to the MATLAB documentation here:
I hope this helps!