In order to better use F2 for data visualization, we need to understand the composition of F2 charts and terms.
In general, F2 chart includes Axis, Geometry, Tooltip, Legend, and may also includes Guide, Annotations.
The basic components of F2 chart is shown below:
Each chart usually contains two axes, x-axis and y-axis in Cartesian coordinate and the angle and radius in polar coordinate. Each axis consists of axis line, tick line, label and grid.
Legend serves as an guide element of the chart, and is used to demonstrate data types and the range of values. It is used to assist in reading the chart and help the user filter the data in chart.
Geometries are shapes such as points, lines, areas. The type of geometry in grammar of graphics determines their type of the generated chart, that is, the actual display after data visualization. Different geometries contain different attributes.
Attributes correspond to visual channels in visual coding and are very important and flexible in grammar of graphics. Different geometries have their own attributes. F2 provides position, color, size and shape these four attributes.
A coordinate is a 2-dimensional positioning system that combines two kinds of position scales and describes how the data to mapped to the canvas where chart is located.
When we touch the chart, the information of the data corresponding to the touch point is displayed in the form of a box, such as the value of the point, the data unit, etc.. Tooltip helps user to obtain the specific information from the chart.
When you need to draw some lines, points or text on a chart, such as the warning line, the highest value, or marking a clear range of areas, the Guide is a very helpful tool.