R-tricks

Short functions to make life easier in R

filter_group()

Filter grouped data and keep each group in which one or more rows match a given condition.

Example: get all cars by manufacturers who make 3 cyl cars:

MASS::Cars93 %>%
    group_by(Manufacturer) %>%
    filter_group(Cylinders==3) %>%
    ungroup() %>%
    select(Manufacturer,Model,Cylinders)

will output

  Manufacturer Model  Cylinders
  <fct>        <fct>  <fct>    
1 Geo          Metro  3        
2 Geo          Storm  4        
3 Subaru       Justy  3        
4 Subaru       Loyale 4        
5 Subaru       Legacy 4        
6 Suzuki       Swift  3   

AddColHere / AddRowHere

Function to add a column / row in the middle of a dataframe e.g.

df <- [a=1:3, b=4:6, c=7:9]

myCol <- 0:2

AddColHere(df, myCol, afterCol = "b")

or

AddColHere(df, myCol, afterCol = 2)

or with dplyr

df %>% AddColHere(myCol,afterCol = "b")

output:

	a	b	myCol	c
1	1	4	0	7
2	2	5	1	8
3	3	6	2	9

fac2num()

Convert the names of each level of a factor to numeric. e.g.

my_factor<-factor(c("1","4","5"))
fac2num(my_factor)

[1] 1 4 5

inf.omit()

remove non-finite values, much like na.omit e.g.

(vec <- c(1, 2, 3/0))

1 2 Inf

inf.omit(vec)

1 2

compareColNames()

compare the column names in two dataframes and output the differences to the command window. e.g.

df1 = data.frame(a=1:3, b=2:4, c=4:6)
df2 = data.frame(a=1:5, b=6:10, d=10:14)
compareColNames(df1, df2)

[1] "These columns are in the first but not the second df:"

[1] "c"

[1] "These columns are in the second but not the first df:"

[1] "d"

rbindSimmilar

like rbind but will omit columns which aren't in both dataframes. Example:

df1 = data.frame(a=1:3, b=2:4, c=4:6)
df2 = data.frame(a=1:2, b=6:7, d=10:11)
(out <- rbindSimmilar(df1, df2))

output:

	a	b
1	1	2
2	2	3
3	3	4
4	1	6
5	2	7

readAllFilesInFolder

Reads in all sheets in all .xlsx files in a given directory, into a list of dataframes, each dataframe named like "-.xlsx" Usage:

myListOfDataframes <- readAllFilesInFolder("/path/to/folder/")