What is boxplot)

What is a boxplot
Box plot is often seen in the literature and is a common representation of data distribution. However, what you see is often not very clear. Therefore, you need to understand the plot process of the box plot and its significance.
Computing process:
1. Calculate the upper quartile, median, and lower quartile.
2 calculate the difference between the upper quartile and the lower quartile, that is, the quartile difference (iqr, interquartile range)
3. Upper and Lower ranges of the box plot. The upper limit is the upper quartile and the lower limit is the lower quartile. Draw a horizontal line at the position of the median inside the box.
4. values greater than 1.5 times of quartile difference in the upper quartile, OR values smaller than 1.5 times of quartile difference in the lower quartile are classified as outliers ).
5. Draw a horizontal line between the two values closest to the upper and lower edges as the tentacles of the boxplot.
6. An abnormal value, that is, an abnormal value that is three times longer than the quartile difference, is expressed as a solid point. A mild abnormal value is an abnormal value between 1.5-3 times the quartile difference, expressed as a hollow point.
7. Add the name and number axis for the boxplot.
In software such as Spss, sigmaplot, R, splus, and origin, it is very convenient to draw a box plot.
The following is an example of a boxplot in R.
Example of boxplot:
Enter the following command in the r Software:
X <-C (25, 45, 50, 54, 55, 61, 64, 68, 72, 75, 75, 78, 79, 81, 83, 84, 84, 84, 85, 86, 86, 86, 87, 89, 89, 90, 91, 91, 92,100)
Boxplot (X)
Plot box plot for vector C.