Define a Decision Table

Match

Sometimes you might want to test a group of conditions and return a value when a true statement is found. You can do this using the match{} keyword. Sounds complicated?

Let's explore some practical examples!

Here you can see how you can determine a salary bonus based on performace. The current Bonus is 0.02 because the value for Performance matches (in other words, is) Exceeds. If the value for Performance was "Meets" the Bonus would be 0.

A more complex example:

You can also combine decision tables with a custom formula to make them easy to reuse. Let's for example define a formula to match scores of students to their grades:

Here we are defining a custom formula called grade(g) that we then use on a table. Can you see how the Grades column is automatically filling the correct score for each student? How cool is that?

Tiers & Slices

There are a lot of instances when you need to use a formula on a number until a certain threshold, and other formulas as that number grows.

For examples:

• Performance gates in a tiered sales commission structure. When someone sells within a certain range, they may earn a higher percentage of commission.
• A progressive tax system where each tax bracket is taxed at a different rate.

Tiers

To make these easier to work on Decipad, we've created a special syntax!

Its called tiers and it slices a number into different levels of tiers, so you can perform calculations using formulas on each tier. At the end, the results are added up for you.

Here's an example for a sales comission scenario.

As YourSales crosses the $100,000 mark, the sales comission goes from 5% to 7%.

Tiers Syntax

Let's unpack the syntax.

• The Tier syntax looks a lot like the table syntax, but you will need to specify <YourNumber> for evaluation.

• Inside {} and before :, you can specify each tier threshold.

• After : you can specify the formula for each level.

• When defining the formulas, you may use the keyword tier to reference <YourNumber> on that tier.

Take a look at this conceptual example:

tiers <YourNumber> {
  1st tier : Formula for 1st tier
  2nd tier : Formula for 2nd tier
  nth tier : Formula for nth tier
  rest: Formula for scenarios greater than the nth tier
}

Optionally, you can specify a maximum and minimum value for your tier system. No matter how big or small your result may be, your tier system will always return between these boundaries.

Check this conceptual example:

tiers <YourNumber> {
  1st tier : Formula for 1st tier
  2nd tier : Formula for 2nd tier
  nth tier : Formula for nth tier
  max: Maximum value
  min: Minimum value
  rest: Formula for scenarios greater than the nth tier
}

Optionally you can use slices and slice instead of tiers and tier.

Tier Examples

Take a look at this example where we calculate income taxes in the UK.

This is the current Income Tax Table in the UK:

Income	Income Tax Band
Up to £12,570	0%
Between £12,571 and £50,270	20%
Between £50,271 and £150,000	40%
Over £150,000	45%

Here is how you build it on Decipad:

On this example, we've combined tiers/slices and a formula definition to make it easier to reuse later. In this case, it allows you to use ÌncomeTaxes() each time you want to know how much someone will pay in income tax in the UK.

For this partical situation, since MyIncomeis £52,000 my taxes are going to be £8,231.8.

Income	Income Tax Band	Tax paid
Up to £12,570	0%	No income tax on the first £12,570
Between £12,571 and £50,270	20%	20% income tax on you next £37,500 income
Between £50,271 and £150,000	40%	40% on the final £1,730 of income
Over £150,000	45%	No income tax paid at his rate

Let's see another example:

Here MyIncomeis £85,000instead of £52,000 and my taxes are going to be £21,431.8 instead of £8,231.8.

To make these calculations easier, you can also use a table:

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Give it a try! How do you see yourself using tiers on your notebook?