具有多个条件的for循环

Question

I have a database with about 5000 rows and I would like to change the data in one column in a special way, if several conditions are true. If the condition is not true, the value will remain the same. This is how the data frame looks like:

> testdata
      A  B  C  D  E  F  G
row1 10 10 50 10 50 70 50
row2 10 10 50 70 50 40 60
row3 30 10 50 70 30 20 50
row4 30 30 50 10 10 50 30
row5 10 10 30 10 30 60 40
...

My plan is to change the data in column G under special conditions like this:

If A = 10 and B = 10 and C = 50 and D = 10 and E = 50 and F = 70, then calculate G - 10

If A = 10 and B = 10 and C = 50 and D = 70 and E = 50 and F = 40, then calculate G - 20

If A = 30 and B = 30 and C = 50 and D = 10 and E = 10 and F = 50, then leave G as it is. ... and so on

I have tried to write a for-loop code, but so far it doesn't work and the other discussions on the inte.net about this topic couldn't help me. I'm absolutely not sure how to write the right code because I'm a RStudio beginner.

Hope you can help me!

Answer 1

testdata <- 
  tibble::tribble(
    ~A,  ~B,  ~C,  ~D,  ~E,  ~F,  ~G,
     10, 10, 50, 10, 50, 70, 50,
     10, 10, 50, 70, 50, 40, 60,
     30, 10, 50, 70, 30, 20, 50,
     30, 30, 50, 10, 10, 50, 30,
     10, 10, 30, 10, 30, 60, 40
  )


library(dplyr)
mutate(testdata, outcome = 
         case_when(
           A == 10 & B == 10 & C == 50 & D == 10 & E == 50 & F == 70 ~  G - 10,
           A == 10 & B == 10 & C == 50 & D == 70 & E == 50 & F == 40 ~  G - 20,
           A == 30 & B == 10 & C == 50 & D == 10 & E == 50 & F == 50 ~  G
         ))

You just have to keep on with your conditions after the last condition.

# A tibble: 5 × 8
      A     B     C     D     E     F     G outcome
  <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>   <dbl>
1    10    10    50    10    50    70    50      40
2    10    10    50    70    50    40    60      40
3    30    10    50    70    30    20    50      NA
4    30    30    50    10    10    50    30      NA
5    10    10    30    10    30    60    40      NA