如何将function应用到R中的每一行dataframe？

Question

I want to apply given function to each row of dataframe and use another values of row, as input parameters/arguments:

Model <- c("H5", "H5", "H5","H4")
Length <- c(6, 6, 6, 6)
Code <- c("030299", "010121","030448","030324")

df <- data.frame(Model,Length,Code)


Model   Length   Code
HS5       6     030299
HS5       6     010121
HS5       6     030448
HS4       6     030324

I want to apply the following code to each row and generate the outcome as a new column

Library(concordance)

concord(sourcevar = (each row of 'Code' column), origin = as.character(character in 'Model' column) , destination = "HS4", dest.digit = as.numeric(number in 'Length' column), all = F))

Documentation Page 6

Answer 1

You can use apply on the rows ( MARGIN = 1 ).

apply(df, MARGIN = 1, function(x) concord(sourcevar = x[3], origin = x[1], destination = "HS4", dest.digit = x[2], all = F))

However, this does not work because there is no conversion dictionary between "HS4" and "HS4", so you can use apply only on the rows that are not HS4:

df$New <- df$Code
df[df$Model != "HS4", ]$New <- apply(df[df$Model != "HS4", ], 1, \(x) concord(sourcevar = x[colnames(df) == "Code"], 
                                               origin = x[colnames(df) == "Model"], destination = "HS4", 
                                               dest.digit = x[colnames(df) == "Length"], all = F))

  Model Length   Code    New
1   HS5      6 030299 030289
2   HS5      6 010121 010121
3   HS5      6 030448 030449
4   HS4      6 030324 030324