绘制每个 x 值的平均值

Question

I plot a function which is based on the results of a curve fit I did in the query. Now I want to see how the curve fit actually fits the average values for every x value. I treid it with a for loop and a groupby.

import matplotlib.pyplot as plt
import numpy as np
import seaborn as sns
plt.style.use('seaborn-colorblind')

x = dataset['mrwSmpVWi']
c = dataset['c']
a = dataset['a']
b = dataset['b']
Snr = dataset['Seriennummer']


dataset["y"] = (c / (1 + (a) * np.exp(-b*(x))))

for number in dataset.groupby('mrwSmpVWi'):
    dataset['m'] = dataset['mrwSmpP'].mean()

fig, ax = plt.subplots(figsize=(30,15))

for name, group in dataset.groupby('Seriennummer'):
    group.plot(x="mrwSmpVWi", y="m", ax=ax, marker='o', linestyle='', ms=12, label =name)
    group.plot(x="mrwSmpVWi", y="y", ax=ax, label =name)

plt.show()

The dataset with the values is huge and not sorted by mrwSmpVWi.

Has someone an idea why I only get a straight line for my average values?

Answer 1

You got to take a look at what you're doing with this line:

for number in dataset.groupby('mrwSmpVWi'):
    dataset['m'] = dataset['mrwSmpP'].mean()

You probably want:

dataset['m'] = dataset.groupby('Seriennummer')['mrwSmpVWi'].transform('mean')

(assuming you were intending to calculate the mean of each group of Serienummer)