Bulk update in subset obtained from dataframe filtering [duplicate]

问题

This question already has answers here:

Updating a subset of a dataframe (2 answers)

Closed 8 months ago.

I have a dataframe, which I filter based on 2 condition as follow:

subset(sales_data, month == 'Jan' & dept_name == 'Production')`

I want to bulk update the value of a particular column(let's say status) of above subset Something like

subset(sales_data, month == 'Jan' & dept_name == 'Production')["status"] <- "Good result"`

I am not sure, how I can do this.

回答1:

You could do

sales_data$status[
 sales_data$month == 'Jan' & sales_data$dept_name == 'Production'] <- "Good result"

Using replace

sales_data$status <- with(sales_data, 
     replace(status, month == 'Jan' & dept_name == 'Production', "Good result"))

---

We can also integrate this in dplyr chain.

library(dplyr)

sales_data %>%
   mutate(status = replace(status, month == 'Jan' & dept_name == 'Production', 
                   "Good result"))

or with case_when

sales_data %>%
 mutate(status = case_when(month == 'Jan' & dept_name =='Production'~"Good result",
                           TRUE ~ status))

subset filter the dataframe based on conditions provided and does not update them.

来源：https://stackoverflow.com/questions/55507593/bulk-update-in-subset-obtained-from-dataframe-filtering