R中的条件值赋值

在以下示例数据中：

keyword <- c("advertising plan","advertising budget",
         "marketing plan",
         "marketing budget",
         "hr plan",
         "hr budget",
         "operation plan",
         "operation budget")
indicator <- c(1,0,1,0,0,1,1,1)
df <- cbind(keyword,indicator)

关键字
#Convert to dataframe if it isn't already
df = as.data.frame(df, stringsAsFactors = FALSE)
#Extract first word of the keyword as the topic
df$Topic = sapply(strsplit(df$keyword," "),function(x) x[1])
#Set all values other than marketing and advertising to blank (or NA if you want)
df$Topic[df$Topic != "marketing" & df$Topic != "advertising"] = ""

keyword <- c("advertising plan","advertising budget",
             "marketing plan",
             "marketing budget",
             "hr plan",
             "hr budget",
             "operation plan",
             "operation budget")
indicator <- c(1,0,1,0,0,1,1,1)
df <- data.frame(keyword, indicator, stringsAsFactors = FALSE)

df[df$keyword %in% c("advertising plan", "advertising budget"), "Topic"] = "Advertising"
df[df$keyword %in% c("marketing plan", "marketing budget"), "Topic"] = "Marketing"

df[grepl("advertising plan|advertising budget", df$keyword), "Topic"] = "Advertising"
df[grepl("marketing plan|marketing budget", df$keyword), "Topic"] = "Marketing"