Radar chart, also known as spider chart or network chart, is a two-dimensional chart type, which aims to draw one or more numerical sequences of multiple quantitative variables. Each variable has its own axis, and all axes are connected to the center of the graph. Let's consider a student's exam results. His scores in ten subjects, such as mathematics, physical education and statistics, ranged from 0 to 20. The radar chart provides an axis for each topic. Through this shape, we can see which topics the students performed well or badly.
The last chart, which only draws a series, shows the performance of a student. A common task is to compare several people. Only a few series are needed to display each group on the same chart. As shown below, it is obvious that Shirley is superior to Sonia in comprehensive performance, except for sports, English and R code.
Suitable for two-dimensional data sets (each data point contains two values of x and y), but only one dimension needs to be compared. Annual sales volume is two-dimensional data, and "year" and "sales volume" are its two dimensions, but only one dimension of "sales volume" needs to be compared.
Histogram uses the height of columns to reflect the difference of data. The naked eye is very sensitive to the height difference and the recognition effect is very good. The limitation of histogram is that it is only suitable for small and medium-sized data sets.
Generally speaking, the X axis of the histogram is the time dimension, and users habitually think that there is a time trend. If the x axis is not a time dimension, it is suggested to distinguish the columns by color to change the user's attention to the time trend.