如何绘制直方图，yaxis 为“对应于每个 x bin 的 y 值的总和”，x 轴为 python 中 x 的 n 个 bin？

Question

Say I have two arrays:

x=np.random.uniform(0,10,100)
y=np.random.uniform(0,1,100)

I want to make n bins between xmin=0 and xmax=10. For each y, there is a corresponding x which belongs to one of these n bins. Say the value corresponding to each bin is initially zero. What I wish to do is add each value of y to its corresponding x's bin and plot a histogram with the x-axis as xmin to xmax with n bins and the y axis as the total of all y values added to corresponding x's bins. How can one do this in python?

Answer 1

First of all, i think its easier to use a bar plot instead of a histogram.

import matplotlib.pyplot as plt
import numpy as np

xmax = 6600
xmin = 6400
x = np.random.uniform(xmin, xmax, 10000)
y = np.random.uniform(0, 1, 10000)
number_of_bins = 100

bins = [xmin]
step = (xmax - xmin)/number_of_bins
print("step = ", step)
for i in range(1, number_of_bins+1):
    bins.append(xmin + step*i)
print("bins = ", bins)

# time to create the sums for each bin
sums = [0] * number_of_bins

for i in range(len(x)):
    sums[int((x[i]-xmin)/step)] += y[i]
print(sums)

xbar = []
for i in range(number_of_bins):
 xbar.append(step/2 + xmin + step*i)
# now i have to create the x axis values for the barplot
plt.bar(xbar, sums, label="Bars")
plt.xlabel("X axis label")
plt.ylabel("Y axis label")
plt.legend()
plt.show()

Here is the new result

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