Filter groups using a lagged column - r

I'm working on creating some error reports and one of the times I'm trying to address is potential errors within the ID column id_1. I've made an alternative id column from various identifying features within the rows that I'm calling id_2. To help, I've also created a date_lag column on date to catch items that were entered within a specific period after the initial entry. The main problem that I'm having is returning the entire group that meets the criteria, including that first entry that would have an NA in the date_lag, or, if I allow the NA values through, I get more than just the items I'm looking for (id_1 1 and 2 below).
Example:
#id_1 where potential errors lie
#id_2 alternative id col I'm using to test
df <- data.table(id_1 = c(1:4, 1:4),
id_2 = c(rep(c("b", "a"), c(2, 2))),
date = c(rep(1,4),rep(20,2), rep(10,2)))
df %>%
group_by(id_2) %>%
mutate(date_lag = date - lag(date)) %>%
filter(between(date_lag, 0, 10) | is.na(date_lag))
# A tibble: 6 x 4
# Groups: id_1 [4]
id_1 id_2 date date_lag
<int> <chr> <dbl> <dbl>
1 b 1 NA
2 b 1 0
3 a 1 NA
4 a 1 0
2 b 20 0
3 a 10 9
4 a 10 0
Expected:
# A tibble: 6 x 4
# Groups: id_2 [4]
id_1 id_2 value val_lag
<int> <chr> <dbl> <dbl>
3 a 1 NA
4 a 1 NA
3 a 10 9
4 a 10 9

Perhaps, we can use diff
library(dplyr)
df %>%
group_by(id_1) %>%
filter(between(diff(date), 0, 10))
-output
# A tibble: 4 x 3
# Groups: id_1 [2]
# id_1 id_2 date
# <int> <chr> <dbl>
#1 3 a 1
#2 4 a 1
#3 3 a 10
#4 4 a 10
Concatenate with NA as the diff returns a length 1 less than the original data
df %>%
group_by(id_2) %>%
filter(between(c(NA, diff(date)), 0, 10))
# A tibble: 5 x 3
# Groups: id_2 [2]
# id_1 id_2 date
# <int> <chr> <dbl>
#1 2 b 1
#2 4 a 1
#3 2 b 20
#4 3 a 10
#5 4 a 10

Related

Function over tidyverse code results in issue with quotes

Example of the problem I'm having with applying a function including tidyverse code. I want to repeat for different variable names, but I'm not sure how to 'unquote'.
Example data:
df <- data.frame(grp=c(1,2,1,2,1), one=c(rep('a', 3), rep('b', 2)), two=c(rep('a', 1), rep('d', 4)))
cn <- colnames(df)[2:ncol(df)]
for(i in cn){
i <- enquo(i)
print(df %>% group_by(grp) %>% count(!!i))
}
# A tibble: 2 x 3
# Groups: grp [2]
grp `"one"` n
<dbl> <chr> <int>
1 1 one 3
2 2 one 2
# A tibble: 2 x 3
# Groups: grp [2]
grp `"two"` n
<dbl> <chr> <int>
1 1 two 3
2 2 two 2
Doing it for a single variable named one; this is the correct output.
df %>% group_by(grp) %>% count(one)
# A tibble: 4 x 3
# Groups: grp [2]
grp one n
<dbl> <fct> <int>
1 1 a 2
2 1 b 1
3 2 a 1
4 2 b 1
You can use map, also can avoid group_by by including grp in count
library(dplyr)
library(purrr)
map(cn, ~df %>% count(grp, .data[[.x]]))
#[[1]]
# grp one n
#1 1 a 2
#2 1 b 1
#3 2 a 1
#4 2 b 1
#[[2]]
# grp two n
#1 1 a 1
#2 1 d 2
#3 2 d 2
You can also use NSE with sym
map(cn, ~df %>% count(grp, !!sym(.x)))

R dplyr::Filter dataframe by group and numeric vector?

I have dataframe df1 containing data and groups, and df2 which stores the same groups, and one value per group.
I want to filter rows of df1 by df2 where lag by group is higher than indicated value.
Dummy example:
# identify the first year of disturbance by lag by group
df1 <- data.frame(year = c(1:4, 1:4),
mort = c(5,16,40,4,5,6,10,108),
distance = rep(c("a", "b"), each = 4))
df2 = data.frame(distance = c("a", "b"),
my.median = c(12,1))
Now calculate the lag between values (creates new column) and filter df1 based on column values of df2:
# calculate lag between years
df1 %>%
group_by(distance) %>%
dplyr::mutate(yearLag = mort - lag(mort, default = 0)) %>%
filter(yearLag > df2$my.median) ##
This however does not produce expected results:
# A tibble: 3 x 4
# Groups: distance [2]
year mort distance yearLag
<int> <dbl> <fct> <dbl>
1 2 16 a 11
2 3 40 a 24
3 4 108 b 98
Instead, I expect to get:
# A tibble: 3 x 4
# Groups: distance [2]
year mort distance yearLag
<int> <dbl> <fct> <dbl>
1 3 40 a 24
2 1 5 b 5
3 3 10 b 4
The filter works great while applied to single value, but how to adapt it to vector, and especially vector of groups (as the order of elements can potentially change?)
Is this what you're trying to do?
df1 %>%
group_by(distance) %>%
dplyr::mutate(yearLag = mort - lag(mort, default = 0)) %>%
left_join(df2) %>%
filter(yearLag > my.median)
Result:
# A tibble: 4 x 5
# Groups: distance [2]
year mort distance yearLag my.median
<int> <dbl> <fct> <dbl> <dbl>
1 3 40 a 24 12
2 1 5 b 5 1
3 3 10 b 4 1
4 4 108 b 98 1
here is a data.table approach
library( data.table )
#creatae data.tables
setDT(df1);setDT(df2)
#create yearLag variable
df1[, yearLag := mort - shift( mort, type = "lag", fill = 0 ), by = .(distance) ]
#update join and filter wanted rows
df1[ df2, median.value := i.my.median, on = .(distance)][ yearLag > median.value, ][]
# year mort distance yearLag median.value
# 1: 3 40 a 24 12
# 2: 1 5 b 5 1
# 3: 3 10 b 4 1
# 4: 4 108 b 98 1
Came to the same conclusion. You should left_join the data frames.
df1 %>% left_join(df2, by="distance") %>%
group_by(distance) %>%
dplyr::mutate(yearLag = mort - lag(mort, default = 0)) %>%
filter(yearLag > my.median)
# A tibble: 4 x 5
# Groups: distance [2]
year mort distance my.median yearLag
<int> <dbl> <fct> <dbl> <dbl>
1 3 40 a 12 24
2 1 5 b 1 5
3 3 10 b 1 4
4 4 108 b 1 98

Create multiple new dataframes based on rows in another dataframe with a for loop in r

I have a dataframe that looks like this:
df <- data.frame(ID = c(1,2,3,4,5,6), Type = c("A","A","B","B","C","C"), `2019` = c(1,2,3,4,5,6),`2020` = c(2,3,4,5,6,7), `2021` = c(3,4,5,6,7,8))
ID Type X2019 X2020 X2021
1 1 A 1 2 3
2 2 A 2 3 4
3 3 B 3 4 5
4 4 B 4 5 6
5 5 C 5 6 7
6 6 C 6 7 8
Now, I'm looking for some code that does the following:
1. Create a new data.frame for every row in df
2. Names the new dataframe with a combination of "ID" and "Type" (A_1, A_2, ... , C_6)
The resulting new dataframes should look like this (example for A_1, A_2 and C_6):
Year Values
1 2019 1
2 2020 2
3 2021 3
Year Values
1 2019 2
2 2020 3
3 2021 4
Year Values
1 2019 6
2 2020 7
3 2021 8
I have some things that somehow complicate the code:
1. The code should work in the next few years without any changes, meaning next year the data.frame df will no longer contain the years 2019-2021, but rather 2020-2022.
2. As the data.frame df is only a minimal reproducible example, I need some kind of loop. In the "real" data, I have a lot more rows and therefore a lot more dataframes to be created.
Unfortunately, I can't give you any code, as I have absolutely no idea how I could manage that.
While researching, I found the following code that may help adress the first problem with the changing years:
year <- as.numeric(format(Sys.Date(), "%Y"))
Further, I read about list, and that it may help to work with a list in a for loop and then transform the list back into a dataframe. Sorry for my limited approach, I hope anyone can give me a hint or even the solution to my problem. If you need any further information, please let me know. Thanks in advance!
A kind of similar question to mine:
Populating a data frame in R in a loop
Try this:
library(stringr)
library(dplyr)
library(tidyr)
library(magrittr)
df %>%
gather(Year, Values, 3:5) %>%
mutate(Year = str_sub(Year, 2)) %>%
select(ID, Year, Values) %>%
group_split(ID) # split(.$ID)
# [[1]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 1 2019 1
# 2 1 2020 2
# 3 1 2021 3
#
# [[2]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 2 2019 2
# 2 2 2020 3
# 3 2 2021 4
#
# [[3]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 3 2019 3
# 2 3 2020 4
# 3 3 2021 5
#
# [[4]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 4 2019 4
# 2 4 2020 5
# 3 4 2021 6
#
# [[5]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 5 2019 5
# 2 5 2020 6
# 3 5 2021 7
#
# [[6]]
# # A tibble: 3 x 3
# ID Year Values
# <dbl> <chr> <dbl>
# 1 6 2019 6
# 2 6 2020 7
# 3 6 2021 8
Data
df <- data.frame(ID = c(1,2,3,4,5,6), Type = c("A","A","B","B","C","C"), `2019` = c(1,2,3,4,5,6),`2020` = c(2,3,4,5,6,7), `2021` = c(3,4,5,6,7,8))
library(magrittr)
library(tidyr)
library(dplyr)
library(stringr)
names(df) <- str_replace_all(names(df), "X", "") #remove X's from year names
df %>%
gather(Year, Values, 3:5) %>%
select(ID, Year, Values) %>%
group_split(ID)

Is it possible to dynamically mutate columns (values in a column have other column names)

So I have one column of a dataframe which contains a value, which is equal to a different column name. For each row, I want to change the value of the column that is named.
df <- tibble(.rows = 6) %>% mutate(current_stage = c("Stage-1", "Stage-1", "Stage-2", "Stage-3", "Stage-4", "Stage-4"), `Stage-1` = c(1,1,1,2,4,5), `Stage-2` = c(40,50,20,10,15,10), `Stage-3` = c(1,2,3,4,5,6), `Stage-4` = c(NA, 1, NA, 2, NA, 3))
A tibble: 6 x 5
current_stage `Stage-1` `Stage-2` `Stage-3` `Stage-4`
<chr> <dbl> <dbl> <dbl> <dbl>
Stage-1 1 40 1 NA
Stage-1 1 50 2 1
Stage-2 1 20 3 NA
Stage-3 2 10 4 2
Stage-4 4 15 5 NA
Stage-4 5 10 6 3
So in the first row, I would want to edit the value in the Stage-1 column because the current_stage column has Stage-1. I've tried using !!rlang::sym:
df %>% mutate(!!rlang::sym(current_stage) := 15)
but I get the error: Error in is_symbol(x) : object 'current_stage' not found.
Is this even possible to do? Or should I just bite the bullet and write a different function?
Within the tidyverse, I think using a long format with gather is the easiest way as suggested by Jack Brookes:
library(tidyverse)
df %>%
rowid_to_column() %>%
gather(stage, value, -current_stage, -rowid) %>%
mutate(value = if_else(stage == current_stage, 15, value)) %>%
spread(stage, value)
#> # A tibble: 6 x 6
#> rowid current_stage `Stage-1` `Stage-2` `Stage-3` `Stage-4`
#> <int> <chr> <dbl> <dbl> <dbl> <dbl>
#> 1 1 Stage-1 15 40 1 NA
#> 2 2 Stage-1 15 50 2 1
#> 3 3 Stage-2 1 15 3 NA
#> 4 4 Stage-3 2 10 15 2
#> 5 5 Stage-4 4 15 5 15
#> 6 6 Stage-4 5 10 6 15
Created on 2019-05-20 by the reprex package (v0.2.1)

Removing mirrored combinations of variables in a data frame

I'm looking to get each unique combination of two variables:
library(purrr)
cross_df(list(id1 = seq_len(3), id2 = seq_len(3)), .filter = `==`)
# A tibble: 6 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 1 2
4 3 2
5 1 3
6 2 3
How do I remove out the mirrored combinations? That is, I want only one of rows 1 and 3 in the data frame above, only one of rows 2 and 5, and only one of rows 4 and 6. My desired output would be something like:
# A tibble: 3 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 3 2
I don't care if a particular id value is in id1 or id2, so the below is just as acceptable as the output:
# A tibble: 3 x 2
id1 id2
<int> <int>
1 1 2
2 1 3
3 2 3
A tidyverse version of Dan's answer:
cross_df(list(id1 = seq_len(3), id2 = seq_len(3)), .filter = `==`) %>%
mutate(min = pmap_int(., min), max = pmap_int(., max)) %>% # Find the min and max in each row
unite(check, c(min, max), remove = FALSE) %>% # Combine them in a "check" variable
distinct(check, .keep_all = TRUE) %>% # Remove duplicates of the "check" variable
select(id1, id2)
# A tibble: 3 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 3 2
A Base R approach:
# create a string with the sorted elements of the row
df$temp <- apply(df, 1, function(x) paste(sort(x), collapse=""))
# then you can simply keep rows with a unique sorted-string value
df[!duplicated(df$temp), 1:2]

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