Hướng dẫn how do you find the variance in python? - làm thế nào để bạn tìm thấy phương sai trong python?

Mô -đun thống kê cung cấp các công cụ rất mạnh mẽ, có thể được sử dụng để tính toán bất cứ điều gì liên quan đến số liệu thống kê. Phương sai () là một trong các hàm như vậy. Hàm này giúp tính toán phương sai từ một mẫu dữ liệu (mẫu là một tập hợp con của dữ liệu dân cư). & NBSP; Chức năng phương sai () chỉ nên được sử dụng khi phương sai của mẫu cần được tính toán. Có một hàm khác được gọi là pvariance (), được sử dụng để tính toán phương sai của toàn bộ dân số. Trong các thống kê thuần túy, phương sai là độ lệch bình phương của một biến so với giá trị trung bình của nó. Về cơ bản, nó đo lường sự lây lan của dữ liệu ngẫu nhiên trong một tập hợp từ giá trị trung bình hoặc trung bình của nó. Giá trị thấp cho phương sai chỉ ra rằng dữ liệu được nhóm lại với nhau và không được phân tách rộng rãi, trong khi giá trị cao sẽ chỉ ra rằng dữ liệu trong tập hợp đã cho nhiều hơn nhiều so với giá trị trung bình. & NBSP; Phương sai là một công cụ quan trọng trong Các ngành khoa học, trong đó phân tích thống kê dữ liệu là phổ biến. Đó là bình phương độ lệch chuẩn của bộ dữ liệu đã cho và còn được gọi là thời điểm trung tâm thứ hai của phân phối. Nó thường được đại diện bởi & nbsp; trong thống kê thuần túy. Varariance được tính bằng công thức sau: & nbsp; & nbsp;variance() is one such function. This function helps to calculate the variance from a sample of data (sample is a subset of populated data). 
variance() function should only be used when variance of a sample needs to be calculated. There’s another function known as pvariance(), which is used to calculate the variance of an entire population.
In pure statistics, variance is the squared deviation of a variable from its mean. Basically, it measures the spread of random data in a set from its mean or median value. A low value for variance indicates that the data are clustered together and are not spread apart widely, whereas a high value would indicate that the data in the given set are much more spread apart from the average value. 
Variance is an important tool in the sciences, where statistical analysis of data is common. It is the square of standard deviation of the given data-set and is also known as second central moment of a distribution. It is usually represented by 

in pure Statistics.
Variance is calculated by the following formula : 
 

Nó được tính toán theo giá trị trung bình của hình vuông bình phương trung bình & nbsp;

 

Cú pháp: Phương sai ([Dữ liệu], Xbar) Tham số: & nbsp; [Dữ liệu]: Một số lặp có số có giá trị thực. & NBSP; Xbar (Tùy chọn) Các giá trị được truyền dưới dạng tham số. Exexceptions: & nbsp; StatisticerError được nâng lên cho dữ liệu-set nhỏ hơn 2 giá trị được truyền dưới dạng tham số. & nbsp; variance( [data], xbar )
Parameters : 
[data] : An iterable with real valued numbers. 
xbar (Optional) : Takes actual mean of data-set as value.
Returntype : Returns the actual variance of the values passed as parameter.
Exceptions : 
StatisticsError is raised for data-set less than 2-values passed as parameter. 
Throws impossible values when the value provided as xbar doesn’t match actual mean of the data-set. 
 

Mã số 1: & NBSP;
 

Python3

import statistics

sample = [

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

0

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

2

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____14

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____16

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

8

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____11

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample set is 0.3656666666666667

4

Variance of Sample set is 0.3656666666666667

5

Variance of Sample set is 0.3656666666666667

6

Variance of Sample set is 0.3656666666666667

7

Đầu ra: & nbsp; & nbsp; 
 

Variance of sample set is 0.40924

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;
Code #2 : Demonstrates variance() on a range of data-types 
 

Python3

Variance of Sample set is 0.3656666666666667

8

Variance of Sample set is 0.3656666666666667

9import

0.3656666666663053

1

Variance of Sample set is 0.3656666666666667

8

0.3656666666663053

3import

0.3656666666663053

5

Các

Các

Các

[6= [8

0.3656666666663053

9

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____41

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

0222

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

11

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

12

Traceback (most recent call last):
  File "/home/64bf6d80f158b65d2b75c894d03a7779.py", line 10, in 
    print(statistics.variance(sample))
  File "/usr/lib/python3.5/statistics.py", line 555, in variance
    raise StatisticsError('variance requires at least two data points')
statistics.StatisticsError: variance requires at least two data points

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1sample 2

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

02

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

17

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Traceback (most recent call last):
  File "/home/64bf6d80f158b65d2b75c894d03a7779.py", line 10, in 
    print(statistics.variance(sample))
  File "/usr/lib/python3.5/statistics.py", line 555, in variance
    raise StatisticsError('variance requires at least two data points')
statistics.StatisticsError: variance requires at least two data points

7

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

20

Các

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

36

Variance of Sample set is 0.3656666666666667

6

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

38

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

41

Variance of Sample set is 0.3656666666666667

6

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

43

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

46

Variance of Sample set is 0.3656666666666667

6

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

48

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

51

Variance of Sample set is 0.3656666666666667

6

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

53

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

56

Variance of Sample set is 0.3656666666666667

6

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

58

Đầu ra: & nbsp; & nbsp; 
 

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;
Code #3 : Demonstrates the use of xbar parameter 
 

Python3

import statistics

sample = [

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

0

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

2

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____14

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____16

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

8

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____11

Đầu ra: & nbsp; & nbsp;

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

3

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

81

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;

Đầu ra: & nbsp; & nbsp; 
 

Variance of Sample set is 0.3656666666666667

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;
Code #4 : Demonstrates the Error when value of xbar is not same as the mean/average value 
 

Python3

import statistics

sample = [

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

0

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

2

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____14

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____16

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

8

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____11

Đầu ra: & nbsp; & nbsp;

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;

Đầu ra: & nbsp; & nbsp; 
 

0.3656666666663053

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;
  
Code #4 : Demonstrates StatisticsError 
 

Python3

import statistics

sample = [

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

0

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

2

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____14

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____16

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

8

Variance of Sample 1 is 15.80952380952381 
Variance of Sample 2 is 3.5 
Variance of Sample 3 is 61.125 
Variance of Sample 4 is 1/45 
Variance of Sample 5 is 0.17613000000000006 

1____11

Variance of Sample set is 0.3656666666666667

2

Variance of Sample set is 0.3656666666666667

19

Đầu ra: & nbsp; & nbsp; 
 

Traceback (most recent call last):
  File "/home/64bf6d80f158b65d2b75c894d03a7779.py", line 10, in 
    print(statistics.variance(sample))
  File "/usr/lib/python3.5/statistics.py", line 555, in variance
    raise StatisticsError('variance requires at least two data points')
statistics.StatisticsError: variance requires at least two data points

& nbsp; & nbsp; mã số 2: trình bày phương sai () trên một loạt các loại dữ liệu & nbsp; & nbsp;
Applications : 
Variance is a very important tool in Statistics and handling huge amounts of data. Like, when the omniscient mean is unknown (sample mean) then variance is used as biased estimator. Real world observations like the value of increase and decrease of all shares of a company throughout the day cannot be all sets of possible observations. As such, variance is calculated from a finite set of data, although it won’t match when calculated taking the whole population into consideration, but still it will give the user an estimate which is enough to chalk out other calculations.