(noun.) the number of observations in a given statistical category.
(noun.) the ratio of the number of observations in a statistical category to the total number of observations.
(noun.) the number of occurrences within a given time period; 'the frequency of modulation was 40 cycles per second'; 'the frequency of his seizures increased as he grew older'.
安娜贝拉录入
校对:谢尔曼