Question

我想计算value显示>20从前一个ncol = 1列（5）的数字1定义的特定日期1997.05.25的次数天。例如，日期>20值显示1997.05.21到value <- c(37,19.75,19.5,14.5,24.75,25,25.5,19.75,19.75,14.25,21.25,21.75,17.5,16.25,14.5, 14.5,14.75,9.5,11.75,15.25,14.25,16.5,13.5,18.25,13.5,11.25,10.75,12,8.5, 9.75,14.75) Date <- c("1997-05-01","1997-05-02","1997-05-03","1997-05-04","1997-05-05", "1997-05-06","1997-05-07","1997-05-08","1997-05-09","1997-05-10", "1997-05-11","1997-05-12","1997-05-13","1997-05-14","1997-05-15", "1997-05-16","1997-05-17","1997-05-18","1997-05-19","1997-05-20", "1997-05-21","1997-05-22","1997-05-23","1997-05-24","1997-05-25", "1997-05-26","1997-05-27","1997-05-28","1997-05-29","1997-05-30", "1997-05-31") ncol <- c(0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)` data <- data.frame(value, Date, ncol) library(data.table) setDT(data)[, ncol := ifelse(Date %in% c("1997-05-05","1997-05-11","1997-05-14", "1997-05-18","1997-05-25"), ncol+1, 0) ]的次数。

以下是变量：

 1. value Date  ncol newcol
 2. 37.00 1997-05-05 1 2
 3. 19.75 1997-05-11 1 2
 4. 19.50 1997-05-14 1 2
 5. 14.50 1997-05-18 1 0
 6. 24.75 1997-05-25 1 0

如何做到最好？非常感谢帮助。

这是我的预期结果：

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rightSwipeGesture.cancelsTouchesInView = YES;
rightSwipeGesture.direction = UISwipeGestureRecognizerDirectionRight;
[self.view addGestureRecognizer:rightSwipeGesture];

Answer 1

如果我理解正确，您可以使用Reduce和shift：

library(data.table)
DT <- data.table(value, Date)

DT[, ncol := Reduce(`+`, shift(value > 20, 1:5, fill = 0))]

这样做：对于DT的每一行，它计算前5行中value - 列大于20的时间，并将其写入列ncol。

如果你想改变这个5排＆＃34;窗口＆＃34;从前5天开始包括当前日期+前4行，您可以将代码更改为：

DT[, ncol := Reduce(`+`, shift(value > 20, 0:4, fill = 0))]

Answer 2

以下是使用dplyr的解决方案：

library(dplyr)

data$Date <- as.Date(data$Date)

data %>%
    filter(between(Date, "1997-05-01", "1997-05-21"),
          value > 20) %>%
    nrow()

计算特定日期和数据范围的天数

2 个答案: