seaborn plot 和 pivot 表中的科学记数法

Question

I m trying to use seaborn plot to plot my usedcar data set and I m getting scientific notation in the x axis instead of the actual number. It affects the pivot data too. Please suggest a way to remove the scientific notation.

Code:

plt.figure(figsize=(15,7))
sns.scatterplot(x='Price_in_Lac',y='Kilometers_Driven',hue='Location',data=df)
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df_hm =df.pivot_table(index = 'Brand',columns ='Location',values ="Price_in_Lac",aggfunc=np.median)
f, ax = plt.subplots(figsize=(15,10))
sns.heatmap(df_hm,   cmap='coolwarm',linewidths=.5, annot=True, ax=ax);

Answer 1

For the scatterplot you can use ax.xaxis.get_major_formatter().set_scientific(False) to remove the scientific notation and ....set_useOffset(False) .

Here is an example using the penguins dataset with lengths converted to nanometers to get larger numbers:

import matplotlib.pyplot as plt
from matplotlib.ticker import StrMethodFormatter
import seaborn as sns

penguins = sns.load_dataset("penguins")
penguins["flipper_length_nm"] = penguins["flipper_length_mm"] * 1000000
penguins["bill_length_nm"] = penguins["bill_length_mm"] * 1000000
plt.figure(figsize=(15, 7))
ax = sns.scatterplot(x='flipper_length_nm', y='bill_length_nm', hue='species', data=penguins)
ax.xaxis.get_major_formatter().set_scientific(False)
ax.xaxis.get_major_formatter().set_useOffset(False)
ax.yaxis.get_major_formatter().set_scientific(False)
ax.yaxis.get_major_formatter().set_useOffset(False)

At the left with the original formatting, at the right with the scientific notation removed:

For the colorbar, you need to get access to its ax , for example using the last created one ( fig.axes[-1] ):

import matplotlib.pyplot as plt
from matplotlib.ticker import StrMethodFormatter
import seaborn as sns
import numpy as np

penguins = sns.load_dataset("penguins")
penguins["flipper_length_nm"] = penguins["flipper_length_mm"] * 1000000
penguins["bill_length_nm"] = penguins["bill_length_mm"] * 1000000

df_hm = penguins.pivot_table(index='sex', columns='species', values="flipper_length_nm", aggfunc=np.median)
fig, ax = plt.subplots(figsize=(10, 5))
sns.heatmap(df_hm, cmap='coolwarm', linewidths=.5, annot=True, ax=ax)
cbar_ax = fig.axes[-1]
cbar_ax.yaxis.get_major_formatter().set_scientific(False)
cbar_ax.yaxis.get_major_formatter().set_useOffset(False)
plt.tight_layout()
plt.show()

PS: If you want a thousands separator, you can use ax.yaxis.set_major_formatter(StrMethodFormatter('{x:,.0f}')) .

As mentioned in the other answer, if you also want to change the format of the annotations, you can use sns.heatmap(...,fmt='.0f') (or fmt=',.0f' to get a thousands separator).

Answer 2

Seaborn's heatmap has a fmt parameter that formats the annotations.

See the doc here .

You can get rid of the scientific notation in the heatmap specifying fmt='.2f' or fmt='.0f'

sns.heatmap(df_hm, cmap='coolwarm', linewidths=.5, annot=True, ax=ax, fmt='.2f');