将年月("yyyy-mm"格式)转换为日期吗?

将年月(

问题描述：

我有一个像这样的数据集:

I have a dataset that looks like this:

Month    count
2009-01  12
2009-02  310
2009-03  2379
2009-04  234
2009-05  14
2009-08  1
2009-09  34
2009-10  2386

我想绘制数据(月份为x值，计数为y值).由于数据中存在空白，因此我想将本月的信息转换为日期.我试过了:

I want to plot the data (months as x values and counts as y values). Since there are gaps in the data, I want to convert the Information for the Month into a date. I tried:

as.Date("2009-03", "%Y-%m")

但是它没有用.怎么了?似乎as.Date()也需要一天，并且无法为该天设置标准值吗?哪个功能可以解决我的问题?

But it did not work. Whats wrong? It seems that as.Date() requires also a day and is not able to set a standard value for the day? Which function solves my problem?

答

尝试一下. (在这里，我们使用text=Lines来保持示例的独立性，但实际上，我们将其替换为文件名.)

Try this. (Here we use text=Lines to keep the example self contained but in reality we would replace it with the file name.)

Lines <- "2009-01  12
2009-02  310
2009-03  2379
2009-04  234
2009-05  14
2009-08  1
2009-09  34
2009-10  2386"

library(zoo)
z <- read.zoo(text = Lines, FUN = as.yearmon)
plot(z)

此数据在X轴上不是很漂亮，但是如果您实际上有更多数据，可以这样做，或者您可以使用?plot.zoo的示例部分中所示的精美X轴代码.

The X axis is not so pretty with this data but if you have more data in reality it might be ok or you can use the code for a fancy X axis shown in the examples section of ?plot.zoo .

上面创建的动物园系列z具有"yearmon"时间索引，如下所示:

The zoo series, z, that is created above has a "yearmon" time index and looks like this:

> z
Jan 2009 Feb 2009 Mar 2009 Apr 2009 May 2009 Aug 2009 Sep 2009 Oct 2009 
      12      310     2379      234       14        1       34     2386

"yearmon"也可以单独使用:

> as.yearmon("2000-03")
[1] "Mar 2000"

注意:

"yearmon"类对象按日历顺序排序.

"yearmon" class objects sort in calendar order.

这将以等距间隔绘制月度点，这可能是想要的；但是，如果希望以不相等的间隔绘制点，这些间隔与每个月中的天数成比例，则将z的索引转换为"Date"类:time(z) <- as.Date(time(z)).

This will plot the monthly points at equally spaced intervals which is likely what is wanted; however, if it were desired to plot the points at unequally spaced intervals spaced in proportion to the number of days in each month then convert the index of z to "Date" class: time(z) <- as.Date(time(z)) .

将年月("yyyy-mm"格式)转换为日期吗?

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