Question

is the largest elements converting the complete chart area​

Answer 1

An area chart combines the line chart and bar chart to show how one or more groups’ numeric values change over the progression of a second variable, typically that of time. An area chart is distinguished from a line chart by the addition of shading between lines and a baseline, like in a bar chart.

Basic area chart: tracking active users by month

This area chart shows the number of active users for a fictional web-based company, computed by month. Values for each month can be measured not just from the vertical position of the top of the shape, but also the colored height between the baseline and top. In this chart, we can see that the number of active users has about doubled from November 2019 to February 2020, and that the rate of user gains has increased over time.

When you should use an area chart

While the example above only plots a single line with shaded area, an area chart is typically used with multiple lines to make a comparison between groups (aka series) or to show how a whole is divided into component parts. This leads to two different types of area chart, one for each use case.

Overlapping area chart

In the case that we want to compare the values between groups, we end up with an overlapping area chart. In an overlapping area chart, we start with a standard line chart. For each group, one point is plotted at each horizontal value with height indicating the group’s value on the vertical axis variable; a line connects all of a group’s points from left to right. The area chart adds shading between each line to a zero baseline. Since the shading for groups will usually overlap to some extent, some transparency is included in the shading so that all groups’ lines can be easily seen. The shading helps to emphasize which group has the largest value based on which group’s pure color is visible.