r：有条件地替换列子集中的值

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我有一个这样的数据框：

I have a dataframe like so:

sport contract start contract end visits spends purchases basket 2013-10-01 2014-10-01 12 14 23 basket 2014-02-12 2015-03-03 23 11 7 football 2015-02-12 2016-03-03 23 11 7 basket 2016-07-17 2013-09-09 12 7 13

我想有条件地更换基于变量体育和合同开始的[4：6]列包含NA。 例如：

I would like to conditionally replace the columns [4:6] with NAs, based on the variables "sport" and "contract start". So for instance:

i1 <- which(df$sport =="basket" & df$contract_start>="2014-01-01")

将对我的条件所在的所有行进行索引遇见。 是否有一段简单的代码可以添加到上述代码中，在上述条件下，它将用NA替换df [4：6]？ 我想结束这样的事情：

will index all the rows in which my conditions are met. Is there an easy piece of code to add to the above, that will replace df[4:6] with NAs given the above conditions? I would like to end up with something like that:

sport contract start contract end visits spends purchases basket 2013-10-01 2014-10-01 12 14 23 basket 2014-02-12 2015-03-03 NA NA NA football 2015-02-12 2016-03-03 23 11 7 basket 2016-07-17 2013-09-09 NA NA NA

谢谢！ A。

Thanks! A.

推荐答案

您只需指定要用NA替换的行和列，然后进行分配 NA ：

You can simply specify the rows and columns that you would like to replace with NA, and assign NA to it:

df[df$sport =="basket" & df$contract_start>="2014-01-01", 4:6] <- NA df # sport contract_start contract_end visits spends purchases # 1 basket 2013-10-01 2014-10-01 12 14 23 # 2 basket 2014-02-12 2015-03-03 NA NA NA # 3 football 2015-02-12 2016-03-03 23 11 7 # 4 basket 2016-07-17 2013-09-09 NA NA NA