r - 如何在 R 中进行一次热编码

Question

每个opportunityID有多个产品 我想要一个二进制列，说明机会是否有此产品。如何做到这一点？

输入

+---+---------------+--------+----------+----------+
|   | Opportunityid | Level  | Product1 | Product2 |
+---+---------------+--------+----------+----------+
| 1 |            10 | Low    | SS       | ISP      |
| 2 |            20 | High   | ISP      | Azure    |
| 3 |            30 | Normal | Azure    | ISP      |
| 4 |            40 |        | SS       |          |
| 5 |            50 |        | ISP      |          |
+---+---------------+--------+----------+----------+

预期输出(检查产品 1 和产品 2)

+---+---------------+--------+----------+----------+--------+---------+-----------+
|   | Opportunityid | Level  | Product1 | Product2 | HasSS? | HasISP? | HasAzure? |
+---+---------------+--------+----------+----------+--------+---------+-----------+
| 1 |            10 | Low    | SS       | ISP      |      1 |       1 |         0 |
| 2 |            20 | High   | ISP      | Azure    |      0 |       1 |         1 |
| 3 |            30 | Normal | Azure    | ISP      |      0 |       1 |         1 |
| 4 |            40 |        | SS       |          |      1 |         |         0 |
| 5 |            50 |        | ISP      |          |      0 |       1 |         0 |
+---+---------------+--------+----------+----------+--------+---------+-----------+

代码

library(caret)
Products <- data.frame(
  Opportunityid=c(10, 20, 30, 40, 50),
  Level=c('Low', 'High', 'Normal', '', ''),
  Product1=c('SS', 'ISP', 'Azure', 'SS', 'ISP'),
  Product2=c('ISP', 'Azure', 'ISP', '',''))


# dummify the data
dmy <- dummyVars(" ~ .", data = Products)
trsf <- data.frame(predict(dmy, newdata = Products))
trsf

PS:我有100多种产品，所以我希望流程自动化

Answer 1

您可以使用 tidyverse 来清理数据:

library(tidyverse)
Products <- data.frame(
  Opportunityid=c(10, 20, 30, 40, 50),
  Level=c('Low', 'High', 'Normal', '', ''),
  Product1=c('SS', 'ISP', 'Azure', 'SS', 'ISP'),
  Product2=c('ISP', 'Azure', 'ISP', '',''), 
  stringsAsFactors = FALSE)

Products %>%
   gather(key, value, Product1:Product2) %>% ## collect all Product columns
   mutate(has = ifelse(value == '', '', 1)) %>%  ## add a dummy variable
   spread(value, has, fill = 0) %>%  ## spread the values back in wider format
   select(-key, -V1) %>% ## remove empty columns and former product column
   group_by(Opportunityid, Level) %>% ## group by to collapse rows
   summarise_at(vars(-(Opportunityid:Level)), funs(max)) ## collapse rows

#   A tibble: 5 x 5
#   Groups:   Opportunityid [?]
#   Opportunityid Level  Azure ISP   SS   
#           <dbl> <chr>  <chr> <chr> <chr>
# 1            10 Low    0     1     1    
# 2            20 High   1     1     0    
# 3            30 Normal 1     1     0    
# 4            40 ""     0     0     1    
# 5            50 ""     0     1     0