使用 R 中的两列值快速查找另一个数据框

Question

I have a data frame (call it 'ModelOutput') with three columns (Trial, DurationRet, DiscountRate) and another (call it 'drdata') with three columns (Scenario, variable, value).

I want to quickly filter drdata$Scenario == ModelOutput$Trial & drdata$variable == ModelOutput$DurationRet to return drdata$value into the ModelOutput$DiscountRate column. Is there a way to do this efficiently?

Here are my two attempts, the first of which fails and the second of which is entirely too slow.

ModelOutput$Trial <- drdata[drdata$Scenario == ModelOutput$Trial & drdata$variable == ModelOutput$DurationRet,"value"]



foreach(row = 1:nrow(ModelOutput)) %do%{
  
  ModelOutput[row, "DiscountRate"] <- drdata[drdata$Scenario == ModelOutput[row, "Trial"] & drdata$variable == as.factor(ModelOutput[row,"DurationRet"]+1),"value"]
  
}

Answer 1

It took me a minute, but I realized joins could do the job I was looking for.

Here is my final code:

ModelOutput <- ModelOutput %>% full_join(drdata, by = c(Trial = "Scenario", DurationRet = "variable"))