`drot:`procedure`xROT`applies a plane rotation matrix to a sequence of ordered pairs:`(x_i , y_i)`, for`i = 1, 2, ..., n`.`X`and`Y`are vector of dimensions`(N-1) * abs(incx) + 1`and`(N-1) * abs(incy) + 1`, respectively.`C`and`S`are respectively the cosine and sine of the plane of rotation.