用月份列表循环作为R中的输入

Question

I am trying to run a loop with months as the input. Moreover, I want to spot the number of times a given topic appears in a specific date. The way I am trying to do so is as follows?

for (i in c("January", "February", "March", "April", 
                "May", "June", "July", "August", "September", "October", "November", "December")){
  print(length(which(data$Date == "i 2005" & data$Maxtopic == 3)))
}

Nevertheless, I get 0 as output for all the dates. Any ideas why?

Cheers,

Answer 1

Try data$Date == sprintf("%s 2005", i) . Your attempt searches for the literal string "i 2005".

However, the table function was designed for this. Use gsub to remove the year:

table(gsub(" 2005", "", data[data$Maxtopic == 3, "Date"], fixed = TRUE)) 

PS: Next time please provide a reproducible example to enable development and testing of solutions.