如何创建 y 轴上的值列表，而不必在 Python 中创建 plot 图形？

Question

I have a piece of code that plots a random walk with a specified number of bins on my y-axis. Is there a way in Python to replicate/recreate the values on my y-axis, without having to plot the graph? Below is the code I've been working on and the method I've tried is to divide the min-max range by the number of wanted bins and thereafter create a list with these values. However, I find my method far from optimal and not close to the results I get by using the below code.

I am greatful for any help on this matter!

import matplotlib.pyplot as plt
import numpy as np
import random

dims = 1
step_n = 2000
step_set = [-1, 0, 1]
origin = np.zeros((1,dims))
random.seed(30)
step_shape = (step_n,dims)
steps = np.random.choice(a=step_set, size=step_shape)
path = np.concatenate([origin, steps]).cumsum(0)


# create subplot
fig, ax = plt.subplots(1,1, figsize=(20, 11))
img = ax.plot(path)
plt.locator_params(axis='y', nbins=20)
y_values = ax.get_yticks() # y_values is a numpy array with my y values 

Answer 1

I am not sure, if I understood your problem correctly. Matplotlib defines the differences between the ticks in a way, that I assume are mostly multiples of 5. But a general approach could be, to calculate a padding based on the bins you want and add/subtract it. For your given example the following gives the same result as ax.get_yticks()

bins = 19
padding = np.ceil((np.max(path) - np.min(path)) / bins)

np.linspace(np.min(path) - padding, np.max(path) + padding, bins, dtype=np.int32)