Box Plot Box
Find useful, welcome to discuss mutual learning together - Follow Me
- Also known as box plot, FIG cassette, box-shaped or a box diagram of FIG., Is used as a display chart dispersion of a set of data information.
- The biggest advantage is not affected by a box plot outlier, it is possible to stably accurately depict the discrete distribution of data, but also facilitate cleaning and data.
example
- There is a set of data: 12,15,17,19,20,23,25,28,30,33,34,35,36,37
1, the lower quartile Q1
Determine the location quartile. Position where Qi = i (n + 1) / 4, where i = 1,2,3. n represents the number of items contained in the sequence.
The location, calculating the corresponding quartile.
Example:
Position Q1 where = (14 + 1) /4=3.75,
Q1 = 0.25 × + 0.75 × third fourth = 0.25 × 17 + 0.75 × 19 = 18.5;
2, the median (second quartile) Q2
Median, i.e., a set of numbers arranged in ascending number of intermediate positions. If the sequence number is an even number, the median of the group is the average of two numbers in the middle.
Example:
Position Q2 where 2 = (14 + 1) /4=7.5,
Q2 = 0.5 × + 0.5 × seventh eighth = 0.5 × 25 + 0.5 × 28 = 26.5
3, upper quartile Q3
Calculated with the lower quartile.
Example:
Position Q3 where 3 = (14 + 1) /4=11.25,
Q3 = 0.75 × X + 0.25 × a twelfth = 0.75 × 34 + 0.25 × 35 = 34.25.
4, the upper limit
The upper limit of the non-maximum value of the abnormal range.
We must first know how interquartile range calculated?
Interquartile IQR = Q3-Q1, the upper limit is = Q3 + 1.5IQR
5, the lower limit
The lower limit of the minimum value of the non-abnormal range.
Lower limit = Q1-1.5IQR
application
- In the EC is generally used in the art
