matplotlib在 pandas DataFrame中绘制日期时间 [英] matplotlib plot datetime in pandas DataFrame

问题描述

我有一个像这样的熊猫数据框training.head()

I have a pandas DataFrame that looks like this training.head()

DataFrame已按日期排序.我想作一个散点图，其中广告活动的日期在x轴上，成功率在y轴上.我可以通过使用training.plot(x='date',y='rate')来获得折线图.但是，当我将其更改为training.plot(kind='scatter',x='date',y='rate')时，出现错误:KeyError:u'no item named date'

The DataFrame has been sorted by date. I'd like to make a scatterplot where the date of the campaign is on the x axis and the rate of success is on the y axis. I was able to get a line graph by using training.plot(x='date',y='rate'). However, when I changed that to training.plot(kind='scatter',x='date',y='rate') I get an error: KeyError: u'no item named date'

为什么我尝试创建散点图时索引列会消失?另外，我敢打赌我需要对该日期字段进行一些操作，以免将它当作简单的字符串来对待，对吗?

Why does my index column go away when I try to make a scatterplot? Also, I bet I need to do something with that date field so that it doesn't get treated like a simple string, don't I?

额外的信用，如果我希望每个帐号用不同的颜色绘图怎么办?

Extra credit, what would I do if I wanted each of the account numbers to plot with a different color?

推荐答案

如果我没记错的话，绘图代码仅考虑数字列.在内部它仅选择数字列，所以这就是为什么会出现键错误的原因.

If I remember correctly, the plotting code only considers numeric columns. Internally it selects just the numeric columns, so that's why you get the key error.

date的dtype是什么?如果是datetime64，则可以将其重铸为np.int64:

What's the dtype of date? If it's a datetime64, you can recast it as an np.int64:

df['date_int'] = df.date.astype(np.int64)

然后您进行绘图.

对于彩色部分，制作一个{account number: color}字典.例如:

For the color part, make a dictionary of {account number: color}. For example:

color_d = {1: 'k', 2: 'b', 3: 'r'}

然后在绘制时:

training.plot(kind='scatter',x='date',y='rate', color=df.account.map(color_d))

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