Displaying Measure Values in Charts
In most chart types, measure values for different categories are communicated based on visual cues. For example, the height of a riser in a bar chart, the size of a slice in a pie chart, or the color or an area of a heatmap all communicate the measure value of the dimension value that they represent. By comparing different areas of the chart, and by using the legend and tooltips, you can quickly identify overall trends in your data.