How to make this function dynamic? R function - r

Question

i have a function in R that generates a table graph picking data from a dataframe and every time i want to pass a different variable (column name from dataframe) i have to repeat the code. So sometimes it can be the variable and sometimes the variableb, other times the variablec... etc.
generates_table_variablea <- function(data) { ## how to pass the column = variablea here like this
####### function(data, column = variablea) .. ???
big_data <- data %>%
group_by(a, b, c, d) %>%
mutate(total_categoria_abs = sum(abs(f))) %>%
mutate(volume_negativo = if_else(variablea < 0, f, 0)) %>%
mutate(volume_positivo = if_else(variablea > 0, f, 0)) %>%
mutate(total = sum(volume_positivo) - sum(volume_negativo)) %>%
mutate(e = if_else(variablea < 0, sum(variablea), 0)) %>%
ungroup() %>%
filter (variablea < 0) %>%
group_by(a, b, c, d) %>%
summarise(e = mean(e), vendas = sum(f*-1), frac_vendas = vendas*-1/mean(total_categoria_abs)) %>%
arrange(e) %>%
ungroup()
big_data$frac_vendas <- round(big_data$frac_vendas, digits = 2)
big_data$e <- round(big_data$e, digits = 0)
}
If I want to change this variable, I have to do the follow:
generates_table_variableb <- function(data) { ## HERE IT WILL BE function(data, column = variableb)...
big_data <- data %>%
group_by(a, b, c, d) %>%
mutate(total_categoria_abs = sum(abs(f))) %>%
mutate(volume_negativo = if_else(variableb < 0, f, 0)) %>% #### HERE I NEED TO CHANGE ALWAYS TO VARIABLEA, VARIABLEB, VARIABLEC...
mutate(volume_positivo = if_else(variableb > 0, f, 0)) %>%
mutate(total = sum(volume_positivo) - sum(volume_negativo)) %>%
mutate(e = if_else(variablea < 0, sum(variableb), 0)) %>%
ungroup() %>%
filter (variableb < 0) %>%
group_by(a, b, c, d) %>%
summarise(e = mean(e), vendas = sum(f*-1), frac_vendas = vendas*-1/mean(total_categoria_abs)) %>%
arrange(e) %>%
ungroup()
big_data$frac_vendas <- round(big_data$frac_vendas, digits = 2)
big_data$e <- round(big_data$e, digits = 0)
}
Having multiple functions doing the same thing is slowing down my code...
How could this be better? All that I want is to pass this column dynamically.

Answer 1

This is one of the way
library(dplyr)
x <- data.frame(v1=1:3, v2=4:6)
f <- function(data, var1){
x %>% select(!!var1)
}
f(x, quo(v1))
You can see more explanation in https://adv-r.hadley.nz/quasiquotation.html

Answer 2

I found a other away that works too:
generates_table_variablea <- function(dataframe, variable) { ## Here pass variable
big_data <- dataframe %>%
group_by(a, b, c, d) %>%
mutate(total_categoria_abs = sum(abs(f))) %>%
mutate(volume_negativo = if_else(.data[[variable]] < 0, f, 0)) %>%
mutate(volume_positivo = if_else(.data[[variable]] > 0, f, 0)) %>%
mutate(total = sum(volume_positivo) - sum(volume_negativo)) %>%
mutate(e = if_else(.data[[variable]] < 0, sum(variablea), 0)) %>%
ungroup() %>%
filter (.data[[variable]] < 0) %>%
group_by(a, b, c, d) %>%
summarise(e = mean(e), vendas = sum(f*-1), frac_vendas = vendas*-1/mean(total_categoria_abs)) %>%
arrange(e) %>%
ungroup()
big_data$frac_vendas <- round(big_data$frac_vendas, digits = 2)
big_data$e <- round(big_data$e, digits = 0)
}
Only replace the variable by .data[[variable]] and you can pass any column inside the function.