循环，将月份列表作为R中的输入(loop with list of months as input in R)

循环，将月份列表作为R中的输入(loop with list of months as input in R)

我试图以数月为输入运行一个循环。 此外，我想要查看特定主题在特定日期出现的次数。 我试图这样做的方式如下？

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))) }

尽管如此，我得到0作为所有日期的输出。 有什么想法吗？

干杯，

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,

最满意答案

试试data$Date == sprintf("%s 2005", i) 。 您尝试搜索文字字符串“i 2005”。

但是， table函数是为此而设计的。 使用gsub删除年份：

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

PS：下次请提供可重复的示例，以便开发和测试解决方案。

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.