We will now examine the What If? dashboard to see what ideas it can generate for our own QlikView documents. The What If? tab is located on the right-hand side of the Sales Analysis tab. It is a reasonably simple example of an input multiplied by measures to display the results. The Slider changes what shows in the Input Box, but the Input Box does not always change the Slider, especially if the number entered is outside the slider range. The sliders look as if you can pick an interval between one and five or between five and ten but, in reality, you are limited to intervals of 5 percent. Manually, you can click in the interval display box and then click on the ellipses (…). This will pop up an Expression Wizard page, where you could enter an expression or just an intermediate number, such as 2.5 or -17.
We can also see that the Selection layout is the same as the other dashboards. Again, this consistency is a good choice.
So, how do the What If ? Input Box percentages work to adjust the numbers in the Straight Table Chart object? Right-click on the Input Box (the first one) where we can type a formula or enter a number. Here, we can see that it is indeed an Input Box object; on the General tab, the properties show that it creates a new variable named vVolume.
The Slider
underneath the nicely formatted Input Box is a Slider/Calendar object using the same variable created by and for the Input Box; the variable is named vVolume.
Now, if we right-click, bring up the properties of Straight Table Chart (Object CH50), and navigate to the Expressions tab, we can see that each of the columns in the Straight Table has an expression. The following screenshot shows this:
Figure 6-8: What If? Straight Table expressions
If we then click on the expression named What if Volume, we can see that the formula is Sum([Sales Quantity])+(Sum([Sales Quantity])*($(vVolume)/100)). It uses the same vVolume variable to multiply the Sales Quantity measure to increase the measure by the percentage entered or picked with the Slider. It is a pretty simple but effective way of creating what-if scenarios.