mean

python基础爬虫案例+数据分析

由 感情迁移 提交于 2020-01-10 03:40:37
最近在做一个课程设计，关于爬取安居客房价信息的，本次用到的框架有 BeautifulSoup xlwt,xlrd requests matplotlib pandas numpy 最终实现下图效果： ** 使用说明： 请先注册安居客账户 之后先运行spider.py 随后运行draw.py ** 爬虫代码 spider.py from bs4 import BeautifulSoup import requests import xlwt import time , random def getHouseList ( url ) : house = [ ] headers = { 'User-Agent' : 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/21.0.1180.71 Safari/537.1 LBBROWSER' } # get从网页获取信息 res = requests . get ( url , headers = headers ) # 解析内容 soup = BeautifulSoup ( res . content , 'html.parser' ) # 房源title housename_divs = soup . find_all (

How to use numpy with 'None' value in Python?

由 女生的网名这么多〃 提交于 2020-01-10 03:27:30
问题 I'd like to calculate the mean of an array in Python in this form: Matrice = [1, 2, None] I'd just like to have my None value ignored by the numpy.mean calculation but I can't figure out how to do it. 回答1: You are looking for masked arrays. Here's an example. import MA a = MA.array([1, 2, None], mask = [0, 0, 1]) print "average =", MA.average(a) Unfortunately, masked arrays aren't thoroughly supported in numpy, so you've got to look around to see what can and can't be done with them. 回答2: You

average list of dictionaries in python

由 ￡可爱￡侵袭症＋ 提交于 2020-01-06 11:14:24
问题 I have a list of dictionary like this data = [{'Name': 'john', 'Height': 176, 'Weight':62, 'IQ':120,..},...] the .. signifies various other integer/float attributes and all elements of the list has same format.. I want to get the average Height, Weight and all other numerical attributes in the cleanest/easiest way. I could not come up with a better way than normal for looping which was too messy... and i don't want to use any external packages 回答1: You can use the following sum([item['Weight'

average list of dictionaries in python

由 荒凉一梦 提交于 2020-01-06 11:11:54
问题 I have a list of dictionary like this data = [{'Name': 'john', 'Height': 176, 'Weight':62, 'IQ':120,..},...] the .. signifies various other integer/float attributes and all elements of the list has same format.. I want to get the average Height, Weight and all other numerical attributes in the cleanest/easiest way. I could not come up with a better way than normal for looping which was too messy... and i don't want to use any external packages 回答1: You can use the following sum([item['Weight'

Determining Maximum and Mean of an User-Provided Array in Java

由 不问归期 提交于 2020-01-05 19:24:28
问题 I am new to coding so be easy on me. I am trying to determine the maximum and mean of an user-provided array using two separate classes (i.e. xyz and a separate xyztester class). I've have my coding but the maximum output is 0.0 and the mean output is one less than the length of the array. Here is my coding - "xyz" class public static double maximum(double[] array){ double max = array[0]; for (int j = 1; j < array.length; j++){ if(array[j] > max){ max = array[j]; } } return max; } public

Determining Maximum and Mean of an User-Provided Array in Java

由 点点圈 提交于 2020-01-05 19:24:10
问题 I am new to coding so be easy on me. I am trying to determine the maximum and mean of an user-provided array using two separate classes (i.e. xyz and a separate xyztester class). I've have my coding but the maximum output is 0.0 and the mean output is one less than the length of the array. Here is my coding - "xyz" class public static double maximum(double[] array){ double max = array[0]; for (int j = 1; j < array.length; j++){ if(array[j] > max){ max = array[j]; } } return max; } public

How to calculate mean of matrix based on column value

由 こ雲淡風輕ζ 提交于 2020-01-05 04:41:10
问题 I have B matrix of N*4 dim. I want calculate the mean of the matrix based on last column values. Last column has repeated values in the range of 1 to 3. I want to calculate the mean of all rows whose last column have same value. I am using this command: l(it:,)=mean(B(i,:)) where it ranges from 1 to 3 in the loop and i has all the indices of rows whose last column=1.When I run this code I get Sub scripted assignment dimension mismatch error . Can anyone point out what is wrong in the command?

Matlab - 8x8 window and finding mean

由 随声附和 提交于 2020-01-05 03:27:19
问题 Say I have a matrix of an image, and I want to do the following: Slide an 8x8 window over the matrix Calculate the mean for each pixel in the matrix How can I do that in matlab , provided that I'm kind of new to coding in matlab. Thanks. 回答1: You could use conv2 with a ones(8) filter, as in I2 = conv2(I, 1.0 / 64.0 * ones(8), 'valid'); . We divide by 64.0 because the "filter" isn't normalized. 回答2: You can also use nlfilter : fun = @(x) mean(x(:)); ans= nlfilter(img,[8 8],fun); But as @s

Matlab - 8x8 window and finding mean

由 試著忘記壹切 提交于 2020-01-05 03:27:07
问题 Say I have a matrix of an image, and I want to do the following: Slide an 8x8 window over the matrix Calculate the mean for each pixel in the matrix How can I do that in matlab , provided that I'm kind of new to coding in matlab. Thanks. 回答1: You could use conv2 with a ones(8) filter, as in I2 = conv2(I, 1.0 / 64.0 * ones(8), 'valid'); . We divide by 64.0 because the "filter" isn't normalized. 回答2: You can also use nlfilter : fun = @(x) mean(x(:)); ans= nlfilter(img,[8 8],fun); But as @s

sample integer values with specified mean

由 五迷三道 提交于 2020-01-04 14:19:17
问题 I want to generate a sample of integer numbers in R with a specified mean. I used mu+sd*scale(rnorm(n)) to generate a sample of n values that has exactly the mean= mu but this generates floating-point values; I would like to generate integer values instead. For example, I would like to generate a sample of mean=4. My sample size n =5, an example of generated values would be {2,6,4,3,5}. Any ideas on how to do this in R while satisfying the constraint of a specific value of the mean? 回答1:
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