How to plot the string with power of ten as the exponential?

Question

I want to plot a scientific title or legend label which is e^(x*10**b).

Here's an example:

import matplotlib.pyplot as plt

data = 5.55e10

plt.title('e$^{%.2e}$'%(data))

And, the actual output is:

The preferred output is:

Mechanic Pig · Accepted Answer · 2022-06-02T12:38:45.967

3

Split the formatted string and format them again:

>>> val = 5.55e10
>>> base, power = f'{val:.2e}'.split('e')
>>> f'e$^{{{base}*10^{{{power}}}}}$'
'e$^{5.55*10^{+10}}$'

Output in matplotlib:

edited Jun 02 '22 at 12:38

answered Jun 02 '22 at 12:32

Mechanic Pig

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score 2 · Answer 2 · answered Jun 02 '22 at 12:39

2

Using a regex:

import matplotlib.pyplot as plt
import re

data = 5.55e10

s = re.sub(r'e([+-]\d+)', r'\\cdot{}10^{\1}', f'e$^{{{data:.2e}}}$')

plt.title(s)

output:

answered Jun 02 '22 at 12:39

mozway

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For scientific counting, I think "\times"(×) is better than "\cdot"(·) – Mechanic Pig Jun 02 '22 at 12:46
@MechanicPig I guess this is a matter of personal preference, I like the cdot. I use × for things like `100×`, `2×3 cm` ;) – mozway Jun 02 '22 at 12:47
1

It may be caused by differences in education. Chinese primary school textbooks will mention that the multiplication sign should not be replaced by a dot in pure numeric expressions :) – Mechanic Pig Jun 02 '22 at 12:53

score 0 · Answer 3 · answered Jun 02 '22 at 12:51

you can do that by extracting the base and exp:

import matplotlib.pyplot as plt
from math import log10, floor



def find_exp_base(number):
    exp = floor(log10(abs(number)))
    return round(number/10**exp, 2), exp 

    
data = 5.55e10
base, exp = find_exp_base(data)

plt.title('e$^{' + str(base) + '*10^{'+ str(exp) + '}}$')
plt.show()

output :

How to plot the string with power of ten as the exponential?

3 Answers3