从数据帧绘制散点图

Question

我有一个数据帧如下：

    Metal                   Cost per m^3/$      volume/mm^3
0   Cast Iron               5996.0             20088.253323
1   Medium Carbon Steel     4301.0             12636.050310
2   Alloy Steel             6490.6             9134.975311
3   Stainless Steels        34621.0            29216.210066
8   Titanium Alloys         76500.0            16303.954297

我想画出成本与体积的关系。 我如何用不同的颜色绘制每个点，并使用金属柱作为图例。在

Answer 1

您可以迭代dataframe的行并使用pyplot.scatter来绘制点。在

import pandas as pd
import matplotlib.pyplot as plt

a = ["Cast Iron", "Medium Carbon Steel", "Alloy Steel",
     "Stainless Steels", "Titanium Alloys"]
b = [5996,4301, 6490,34621,76500]
c = [ 20088.253323, 12636.050310, 9134.975311, 29216.210066,16303.954297]

df = pd.DataFrame({"Metal":a, "cost":b, "volume":c})

for row in df.iterrows():
    plt.scatter(row[1]["cost"], row[1]["volume"], 
                c=plt.cm.jet(row[0]/float(len(df))), label=row[1]["Metal"])

plt.legend()
plt.show()