如何在R中实现excel函数“偏移”？

Question

有人知道如何在r中实现excel函数“offset”吗？

在excel中很容易做到这一点，但是在r中做到这一点就太复杂了。

我在这里附上数据和结果。我想做的是根据data1的年龄信息从data2中提取人口。

例如2008年，孩子6岁上小学，所以result数据框的第一行应该是2008年6岁的数字，但是2010年，孩子上小学7 岁上学，所以我需要告诉 R 在 2009 年查找 7 岁的值 data2。

另一件事是如何让 R 将不同年龄段的人口数相加。在result数据框中，对于“在读小学的孩子的行数”，2008年应该将6岁到（6+6）的所有孩子数相加，但在2010年应该将 7 岁到 (7+5) 岁之间的所有儿童数相加..

有人知道如何解决这个问题吗？我正在帮助孩子们，如果你能帮助我，那就太好了..

非常感谢。

data1 = data.frame(item = c("Age for primary school","Duration for primary school", "Duration for middle school", "duration for high school"), 
                  '2008' = c(6, 6, 4, 3),  
                  '2009' = c(6, 6, 4, 3), 
                  '2010' = c(7, 5, 4, 3),  
                  '2011' = c(7, 5, 4, 3)) 

data2 = data.frame('population by age' = seq(3, 24, by = 1), 
                   '2008' = c(145391,
                              140621,
                              136150,
                              131944,
                              127968,
                              124209,
                              120650,
                              117163,
                              113674,
                              110207,
                              106871,
                              103659,
                              100398,
                              97017,
                              93584,
                              90240,
                              86957,
                              83783,
                              80756,
                              77850,
                              75003,
                              72226
                   ),  
                    '2009' = c(148566,
                               143943,
                               139367,
                               135083,
                               131052,
                               127237,
                               123628,
                               120213,
                               116826,
                               113381,
                               109915,
                               106574,
                               103346,
                               100058,
                               96644,
                               93175,
                               89788,
                               86455,
                               83241,
                               80192,
                               77279,
                               74422
                    ), 
                   '2010' = c(152330,
                              147261,
                              142555,
                              138172,
                              134071,
                              130214,
                              126559,
                              123099,
                              119825,
                              116538,
                              113134,
                              109669,
                              106320,
                              103075,
                              99760,
                              96312,
                              92805,
                              89372,
                              85988,
                              82733,
                              79661,
                              76739
                   ),  
                   '2011' = c(156630,
                              151387,
                              146491,
                              141905,
                              137593,
                              133545,
                              129737,
                              126124,
                              122678,
                              119397,
                              116093,
                              112666,
                              109174,
                              105791,
                              102505,
                              99159,
                              95699,
                              92193,
                              88759,
                              85373,
                              82123,
                              79065
                   )) 

result <- data.frame(item = c("number of children with primary school entry age",
                       "number of children who are in primary school",
                       "numer of children who are in completing primarys school"),
                       #"number of children who are in middle school",
                       #"number of children who are completing middle school",
                       #"number of children who are in high school",
                       #"number of children who are completing high school"),
                       "2008" = c(131944,845815,110207),
                       "2009" = c(135083,867420,113381),
                       "2010" = c(134071,750306, 116538),
                       "2011" = c(137593,769074,119397)
)

Answer 1

为了孩子们！

as.data.frame(
mapply(function(x,y) {
  c(y[x[1]-2],                       # first acceptable age
    sum(y[(x[1]-2):(x[1]-2+x[2])]),  # sum within range
    y[x[1]-2+x[2]])                  # last acceptable age
  },
  data1[-1],data2[-1])
)

#    X2008  X2009  X2010  X2011
# 1 131944 135083 134071 137593
# 2 845815 867420 750306 769074
# 3 110207 113381 116538 119397