How do I write formulas for calculated tests?

  • Updated

You can write any formula with these signs:

  • + for Plus
  • - for Minus
  • * for Multiplication
  • / for Division
  • ( or ) for Parenthesis
  • Math.pow(variable/number, power)
    For example: Math.pow(b; 0.67) when your want b^0,67
  • Math.Log(variable/number) for natural logarithm (base e)
    For logarithms of base 10 you just need to divide a natural logarithm by logarithm base 10 like this: Math.Log(x) / Math.Log(10)
  • as well as the variables you get from adding other tests. Variables will be letters going from "a", "b" and so forth.
  • and a few special variables:
    • YY or yy which represents "age" in whole number, for example 20 as in 20 years old
    • YF or yf which represents "age" as a fractional number, for example 20,5 if the person is 20 and a half years old.
    • Some coefficients to enable Khamis-Roche expected height calculations (see example below).

Note: You can add other calculated or combined tests as variables. We emphasise this here because it wasn't always possible. So if you wanted to try that before, now it works :-) 

If you're in need of complex formulas and you can't figure it out with these instructions here, don't hesitate to contact us at support@sidelinesports.com and we'll try our best to help!

Examples

1. BMI (using two tests)

This is how we would setup a calculated test showing BMI using two other tests (weight and height):

BMI.png


2. Speed in 100 meters sprint (changing unit)

This is how we would setup a calculated test showing a a 100m sprint result in km/h instead of seconds:

Speed_in_100m_sprint__km_h_.png

 

3. Sinclair score (using power and logarithmic functions)

Here's an example using both Math.pow and Math.Log(x). Let's say we want to be able to calculate the Sinclair score for an athlete in Olympic Weightlifting. Here's the formula (for men) to calculate the Sinclair coefficient: 10^(0.722762521 * (LOG10(Bodyweight / 193.609))^2)

So we need to use both Math.pow for the power (^) and also Math.Log(bw) / Math.Log(10) for the LOG10(bw)

Notice we're dividing here the natural logarithm Math.Log(x) by Math.Log(10) to get the logarithm of base 10.

Then we use this coefficient to multiply with the actual weight lifted. So our formula would be something like this:

Sinclair for men

[TOTAL]*Math.pow(10;0.722762521*(Math.pow(Math.Log([BODYWEIGHT]/193.609)/Math.Log(10);2)))

Like this (where we use variable "a" for the weight)

sinclair-for-men-xps.png

which gives the result we wish for when compared to the web:
sinclair-for-men-web.png


4. Height prediction (using Khamis-Roche variables)

Here we need to use the special Khamis-Roche variables we provide. 

The formula for boys is:
krb1+krb2*a+krb3*b+krb4*(c+d)/2

and girls:
krg1+krg2*a+krg3*b+krg4*(c+d)/2

And you need to involve 4 tests that contain information about the athletes height and bodyweight as well as the height of their parents.

Note: If you copy the formula strings here above, you need to make sure you add the tests in the same order (so variable a is the height test, variable b is the bodyweight test, variable c is the father's height test and variable d is the mother's height test).

Here's an example for the expected height of a boy using the Khamis-Roche estimation:
height-prediction-calculated-test.webp