For loops? Including rows in a dataframe by the missing values of factor levels

问题

Good morning

I have a dataset of fisheries data with several variables that look like this:

ID              Day      Month   Year  Depth  Haul number  Count LengthClass     
H111200840       11        1     2008   -80       40        4      10-20
H111200840       11        1     2008   -80       40        15     20-30
H29320105        29        3     2010   -40       5         3      50-60
H29320105        29        3     2010   -40       5         8      60-70

The column ID is a unique ID made by paste the columns day,month,Year and Haul.number. As you can see for the same ID I have data of different Length Class. En each Haul, fish from different lengths are captured.

However, LengthClass is a factor variable with the following levels: 10-20, 20-30, 30-40, 40-50 and fish of a certain length class that is not captured in a Haul is not recorded in the dataset.

I need to include in the above data.frame example new rows for each ID with the missing levels of LengthClass.

The missing Length classes should have a Count of 0 but the rest of the variables have to be the same.

This is an example of what I would like

 ID              Day      Month   Year  Depth  Haul number  Count LengthClass     
  H111200840       11        1     2008   -80       40        4      10-20
  H111200840       11        1     2008   -80       40        15     20-30
  H111200840       11        1     2008   -80       40        0      30-40
  H111200840       11        1     2008   -80       40        0      40-50
  H111200840       11        1     2008   -80       40        0      50-60
  H29320105        29        3     2010   -40       5         3      40-60
  H29320105        29        3     2010   -40       5         8      50-60
  H29320105        29        3     2010   -40       5         0      10-20
  H29320105        29        3     2010   -40       5         0      20-30
  H29320105        29        3     2010   -40       5         0      30-40

Is there anyway to do this in R? I have tried for loops with if arguments but with no luck and also the example of this post:

Thanks for any advice in advance

回答1:

You can use tidyr for this.

First use tidyr::complete to fill in all the combinations of LengthClass, specifying that Count should be filled in as 0.

Then sort the data and use tidyr::fill to fill in the same values for the other columns (other than ID, LengthClass, and Count).

Create Data

library(tidyr)
library(dplyr)


df <- readr::read_csv(
'ID,Day,Month,Year,Depth,Haul_number,Count,LengthClass
H111200840,11,1,2008,-80,40,4,10-20
H111200840,11,1,2008,-80,40,15,20-30
H29320105,29,3,2010,-40,5,3,50-60
H29320105,29,3,2010,-40,5,8,60-70') %>% 
  mutate(LengthClass = as.factor(LengthClass))

df
#> # A tibble: 4 x 8
#>           ID   Day Month  Year Depth Haul_number Count LengthClass
#>        <chr> <int> <int> <int> <int>       <int> <int>      <fctr>
#> 1 H111200840    11     1  2008   -80          40     4       10-20
#> 2 H111200840    11     1  2008   -80          40    15       20-30
#> 3  H29320105    29     3  2010   -40           5     3       50-60
#> 4  H29320105    29     3  2010   -40           5     8       60-70

Fill in the extra rows

df %>% 
  group_by(ID) %>% 
  complete(LengthClass, fill = list(Count = 0)) %>% 
  arrange(ID, Day) %>% 
  fill(-ID, -LengthClass, -Count, .direction = "down") %>% 
  ungroup()

#> # A tibble: 8 x 8
#>           ID LengthClass   Day Month  Year Depth Haul_number Count
#>        <chr>      <fctr> <int> <int> <int> <int>       <int> <dbl>
#> 1 H111200840       10-20    11     1  2008   -80          40     4
#> 2 H111200840       20-30    11     1  2008   -80          40    15
#> 3 H111200840       50-60    11     1  2008   -80          40     0
#> 4 H111200840       60-70    11     1  2008   -80          40     0
#> 5  H29320105       50-60    29     3  2010   -40           5     3
#> 6  H29320105       60-70    29     3  2010   -40           5     8
#> 7  H29320105       10-20    29     3  2010   -40           5     0
#> 8  H29320105       20-30    29     3  2010   -40           5     0

来源：https://stackoverflow.com/questions/44271398/for-loops-including-rows-in-a-dataframe-by-the-missing-values-of-factor-levels

标签

loops

if-statement