在matplotlib中为列表/数组绘制散点图 [英] plotting a scatter plot for list/array in matplotlib

问题描述

通过浏览互联网上的示例，我浪费了很多时间.但是我只是想不出为什么我不能针对整数列表绘制一个datetime.date对象列表的简单图形

I have wasted so much time looking through the examples given on internet. But I just cant figure out why can't I plot a simple graph of a list of datetime.date objects against a list of integers

     appleProd1     appleProd2       appleProd3       appleProd4 ..... 70 Products

apple.com  2010-09-12     2008-01-01       2009-03-02        .......................

我想绘制启动日期的散点图，其中x轴为日期，y轴为产品.而我这样做

I wanted to plot a scatter plot for the launch dates with x axis as dates and y axis as the products. And I do this

plt.subplot(1, 1, 1)
product_list = []
label_ticks = []
date_list = []
yval = 1

for prod, date in df.iteritems():  #date is a datetime.date object
    date = pd.to_datetime(date)   
    product = prod
    date_list.append(date)
    prod_list.append(prod)
    label_ticks.append(yval)

    yval+=1

plt.plot_date(date_list, label_ticks)

最后一行plt.plot给我一个错误，提示TypeError: float() argument must be a string or a number.我也尝试将两个列表都转换为numpy数组，并使用相同的plt.scatter.同样的错误.两个列表的长度相同.也参考了此网站

The last line plt.plot gives me an error saying TypeError: float() argument must be a string or a number . I have also tried converting both the lists to numpy array and use same plt.scatter. Same error. Length of both lists is same. Referred to this site also

http://matplotlib.org/api/pyplot_api.html#matplotlib. pyplot.scatter

有些日期也是南.因此，使用date2num进行转换会在此处产生错误.

Some dates are Nan also. So converting using date2num is giving error there.

推荐答案

我弄清楚了问题所在.在date_list中确实存在一些字符串值，因此抱怨plt.plot. plt.plot可以很好地与datetime.date值列表一起使用.无需将datetime.date转换为任何其他格式.

I figured out what the problem was. There were indeed some string values in the date_list so the plt.plot complained. The plt.plot works just fine with a list of datetime.date values. There is no need to convert the datetime.date to any other format.

这篇关于在matplotlib中为列表/数组绘制散点图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！