How to replace values of a character column based on the occurrence of specific strings in another c-CodePudding

I am struggling with replacing a string at a specific row of my data frame.

In this example, there are mistakes in the class1 column, so I need to change two species classes.

Here is my code:

class1 <- c("Sarcopterygii", "Actinopterygii", "Actinopterygii", 
            "Actinopterygii", "Actinopterygii", "Actinopterygii", 
            "Actinopterygii", "Insecta", "Insecta")

Species1 <-c("Protopterus aethiopicus","Synodontis ruandae",
             "Synodontis afrofischeri", "Hyperolius cinnamomeoventris", 
             "Schilbe intermedius", "Hoplobatrachus occipitalis",
             "Raiamas salmolucius","Trithemis pluvialis","Trithemis donaldsoni")

count1 <- c(12, 2, 32, 4, 6, 7, 8, 13, 10)

Dataset1 <- data.frame(class1, Species1, count1)

I wanted to replace the "Actinopterygii" genus with "Amphibia" for the species "Hyperolius cinnamomeoventris", and also do the same for the species "Hoplobatrachus occipitalis"

CodePudding user response：

It sounds like you're just trying to change two specific values? If so, I would just use base R subsetting:

## Find the species for which the class needs replacing:
rows_to_fix <- Dataset1[["Species1"]] %in% c("Hyperolius cinnamomeoventris", "Hoplobatrachus occipitalis")

## At those elements, replace Class1 with "amphibia"
Dataset1[["Class1"]][rows_to_fix] <- "amphibia"

One advantage of this approach is that it makes it clearer that you're just tweaking a couple of specific errors, rather than generalising for a set of rules

CodePudding user response：

I'm not sure to have understood your goal but here is the main idea with dplyr::case_when

library(dplyr)
Dataset1 %>% 
  mutate(class1 = case_when(class1 == "Actinopterygii" ~ "Hyperolius cinnamomeoventris", TRUE ~ class1))

CodePudding user response：

Try this:

rename Species1

Dataset1[Dataset1$class1 == "Actinopterygii" & Species1 == "Hyperolius cinnamomeoventris", "Species1"] <- "Amphibia"

Dataset1[Dataset1$class1 == "Actinopterygii" & Species1 == "Hoplobatrachus occipitalis", "Species1"] <- "Amphibia"

group dataframe

Dataset2 = Dataset1 %>% group_by(class1, Species1) %>% summarise(count1 = sum(count1))