我有以下数据集(请参阅下面的加载数据集)
ID Date qty
1 ID25 2007-12-01 45
2 ID25 2008-01-01 26
3 ID25 2008-02-01 46
4 ID25 2008-03-01 0
5 ID25 2008-04-01 78
6 ID25 2008-05-01 65
7 ID25 2008-06-01 32
8 ID99 2008-02-01 99
9 ID99 2008-03-01 0
10 ID99 2008-04-01 99
我想创建一个数据透视表。我使用以下命令执行此操作,并且似乎工作正常:
pivottable <- xtabs(qty ~ ID + Date, table)
输出如下:
ID 2007-12-01 2008-01-01 2008-02-01 2008-03-01 2008-04-01 2008-05-01 2008-06-01
ID25 45 26 46 0 78 65 32
ID99 0 0 99 0 99 0 0
但是,对于 ID99,只有 3 个周期的值,其余的被标记为“0”。我想在第一个表中没有值的字段中显示 NA 。我想得到一个如下所示的表格:
ID 2007-12-01 2008-01-01 2008-02-01 2008-03-01 2008-04-01 2008-05-01 2008-06-01
ID25 45 26 46 0 78 65 32
ID99 NA NA 99 0 99 NA NA
关于如何做到这一点的任何建议?
加载数据集:
table <- structure(list(ID = structure(c(1L, 1L, 1L, 1L, 1L, 1L, 1L, 2L,
2L, 2L), .Label = c("ID25", "ID99"), class = "factor"), Date = structure(c(7L,
1L, 2L, 3L, 4L, 5L, 6L, 2L, 3L, 4L), .Label = c("01/01/2008",
"01/02/2008", "01/03/2008", "01/04/2008", "01/05/2008", "01/06/2008",
"01/12/2007"), class = "factor"), qty = c(45L, 26L, 46L, 0L,
78L, 65L, 32L, 99L, 0L, 99L)), .Names = c("ID", "Date", "qty"
), class = "data.frame", row.names = c(NA, -10L))
table$Date <- as.POSIXct(table$Date, format='%d/%m/%Y')