Tornado diagrams or charts are a special type of Bar chart, where the data categories are listed vertically instead of the standard horizontal presentation, and the categories are ordered so that the largest bar appears at the top of the chart, the second largest appears second from the top, and so on when sorted descending. They are so named because the final chart visually resembles either one half of a complete tornado. They are ideal for representing 2 values that need to be compared across any dimension.
Metrics: 2 metrics are required. Attributes: 1 or more attributes are required. Use as Filter Option - Available
In the example below Profit and Profit Forecast are represented by the bars over time attribute Month. Also, the chart below is sorted by Profit in descending order in the editor section.
We can make the sparkline chart as a combinational chart by changing the series type in the series tab. Instead of a bar, we can make a chart to show either line/area/column/scatter.
In the case when tornado chart series is changed to either line/scatter/area, we can change the marker to any shape listed in ‘marker type’ in the ‘marker’ tab.
In the business point of view, certain part of the chart needs to be highlighted to draw more attention from the desicion makers. For example, highlight the stores where total sales is greater than a specific value or highlight the top 10 products whose sales is high during last year’s winter. Thresholds are very useful objects in these use cases.
Thresholds will display some conditional formatting in a chart to highlight certain data points depending on predefined criteria.The criteria are attribute or metric qualifications. If a qualification’s expression evaluates to TRUE, the report displays the threshold. We can also include markers in thresholds.
To apply thresholds in vitara charts, hover the cursor on the chart. Vitara chart will display an ‘Edit’ button. When you click on this ‘Edit’ button the properties window will pop out. Select the thresholds tab to open threshold editor. In the window you can add a new threshold or delete any existing threshold or modify the existing threshold.
Note: From 4.6 version we can apply thresholds using attributes. The source drop down box in the threshold editor window will list all the attributes and metrics in the chart. we can select an attribute as source and define a threshold condition. The target of the threshold depends on the series of the chart. This means, if the chart series is created using metrics then target drop down box will display the metrics. If we enabled ‘color by’ mode, by adding an attribute to the ‘color by’ drop zone in the dossier’s editor panel, the chart series will be created using attributes. In this case the threshold target drop down box will show all the elements of attribute used in the color by drop zone. In this case we can set threshold target using attribute.
In the threshold editor window apply source, target, threshold condition and the other related information to set a threshold on the chart.
After giving all the inputs click on ‘Apply’ button.
Play by - animation shows the chart for each element of the first attribute. For more details about the play by feature please refer to play-by.
The steps to set a background image for all Vitara charts are explained in backgroundImage.
Tornado supports small multiples feature. Small multiples is explained in smallMultiples.