How-To

Stacked Bar Graphs

Stacked bar graphs are an excellent way to show related data. To demonstrate how to create a stacked graph, we’ll be creating a stacked graph showing the High, Low, and Moderate risk inspections that occurred in San Francisco in 2015.

We want to graph inspections per day, regardless of time, so we first use the column menu to truncate the date so that only Month, Day and Year remain. Filter your data to only show the dates that you would like to appear on your graph.

Next, go to Charts and hit +Add Chart, and choose to create a stacked bar graph. Drag the column with the truncated dates to the X axis. This will automatically create a graph that counts the number of rows that exists for each date.

In the X Axis box, click the arrow to the right of the DATE – Day column name and change the axis type from continuous to discreet. This tells Sigma that each date should be treated as an individual data point rather than part of a continuum of time.

To show the risk category of the violations each day, drag the column“RiskCategory” to the Color box. This will divide the bars in the graph into 3 sections to represent High Risk, Low Risk and Moderate Risk violations.