Coordinate problem between get2d () and cvset2d () in opencv

The function prototype of cvget2d () is:
Cvscalar cvget2d (const cvarr * arr, int idx0, int idx1 );

The function returns a cvscalar container with two coordinates in the parameter. idx0 represents the row, that is, the height, corresponding to Y in our normal coordinate system, and idx1 represents the column, that is, the width corresponds to X in our normal coordinate system, and cvset2d () is similar. Therefore, when using cvset2d () and cvget2d (), pay attention to the sequence of coordinates.

Cvapi (void) cvset2d (cvarr * arr, int idx0, int idx1, cvscalar value );

Coordinate problem between get2d () and cvset2d () in opencv