示例数据如下:
browsersc(3L, 3L, 3L, 3L, 2L, 2L, 2L, 1L, 5L, 5L, 4L), ...., 6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), .Label = c("Chrome 10.0", "Firefox 3.5", "Firefox 3.6",...3L, 3L, 2L, 2L,2L, 1L, 5L, 5L, 4L), .Label = c("Chrome", "Firefox", "MSIE","Opera", "Safari"), class...= "factor"), version = structure(c(5L,6L, 7L, 8L, 2L, 3L, 4L, 1L, 10L, 11L, 9L), .Label = c("Chrome...3L, 3L, 3L, 3L, 2L, 2L, 2L, 1L, 5L, 5L, 4L), .Label = c("Chrome", "Firefox