通过添加带有动态名称和记录值的新列来展开数据框

Question

我当前的数据框是格式：

     name               GRADUATION_RATE                      varname count
  Example Name 1                  13.0                    Bus Stops   251
  Example Name 1                  13.0            Childcare Centers    87
  Example Name 2                  14.0                    Bus Stops   300
  Example Name 2                  14.0            Childcare Centers    60

我想扩展数据框，以便基于变量名称的计数创建新列，因此将有与唯一的varnames数量一样多的新列。因此，上述预期输出将是：

     name               GRADUATION_RATE     Bus Stops_count Childcare centers_count 
  Example Name 1                  13.0                  251                      87
  Example Name 2                  14.0                  300                      60

我猜这就像Dplyr融化的相反，但我不确定该怎么做。

Answer 1

reshape2

# library(reshape2)
reshape2::dcast(dat, name + GRADUATION_RATE ~ varname, value.var = "count")
#             name GRADUATION_RATE Bus Stops Childcare Centers
# 1 Example Name 1              13       251                87
# 2 Example Name 2              14       300                60

（这也可以与data.table :: dcast一起使用，如果您有data.table -Object。）

tidyr

# library(tidyr)
tidyr::pivot_wider(dat, names_from = "varname", values_from = "count")
# # A tibble: 2 x 4
#   name           GRADUATION_RATE `Bus Stops` `Childcare Centers`
#   <chr>                    <dbl>       <int>               <int>
# 1 Example Name 1              13         251                  87
# 2 Example Name 2              14         300                  60

---

data

dat <- structure(list(name = c("Example Name 1", "Example Name 1", "Example Name 2", "Example Name 2"), GRADUATION_RATE = c(13, 13, 14, 14), varname = c("Bus Stops", "Childcare Centers", "Bus Stops", "Childcare Centers"), count = c(251L, 87L, 300L, 60L)), class = "data.frame", row.names = c(NA, -4L))