Dataset Calculation is used to perform calculations on existing Datasets, in order to create new Datasets.

For example, you might want to make these new Datasets:

•	Distance a wheel has travelled = Circumference of the wheel x Motor Rotations
•	Average light intensity = (Colour Sensor 1 (Ambient Light Intensity) + Colour Sensor 2 (Ambient Light Intensity)) divided by 2
•	Closest object = Minimum value of Ultrasonic Sensor 1, Ultrasonic Sensor 2, and Ultrasonic Sensor 3

In each case, you take one or more existing Datasets, and perform mathematical functions to create a new Dataset. See (Formula Field) for more.

You can open Dataset Calculation by clicking the Dataset Calculation tab.

Dataset Calculation tab

Formula Field

Calculated Dataset Name

Calculated Dataset Unit

Calculate

Functions List

Datasets

Formula Field

The Formula Field is used to create an equation to generate the new Dataset. The Datasets you collect may have different names.

This table gives the equations for the examples above.

New Dataset	Formula
Distance a wheel has travelled (assuming 17.5 cm circumference)	Motor_Rotation _pB *17.5
Average Light Intensity of two Colour Sensors	Avg(Color_Sensor_p3; Color_Sensor_p2) OR (Color_Sensor_p3 + Color_Sensor_p2) / 2
Closest object	Min(Ultrasonic_Sensor_pB; Ultrasonic_Sensor_pC; Ultrasonic_Sensor_pD)

Calculated Dataset Name

This is the ID of your dataset. You can rename your calculated dataset to something more meaningful.

Calculated Dataset Unit

Give your new Dataset a unit of measurement. For example, the distance travelled may be centimetres.

Calculate

Once a formula has been created in the Formula Field, click Calculate to generate a new Dataset and place it on the Graph Area. This Dataset will be given its own Y-Axis. You can change the Colour and Plot Style using the Dataset Table tab.

Functions List

Functions can be used to perform calculations on your Datasets.

Function Name	Function term	Definition
Add	+	Add a constant or another dataset to the original
Subtract	-	Subtract a constant or another dataset from the original
Multiply	*	Multiply a dataset by a constant or another dataset
Divide	\	Divide a dataset by a constant or another dataset
Absolute Value	Abs	Returns the absolute value of the specified number
Average	Avg	Returns the average value of all the specified datasets
Floor	Floor	Returns the largest whole number less than or equal to the specified number
Ceiling	Ceil	Returns the smallest whole number greater than or equal to the specified number
Minimum	Min	Returns the smaller of the specified set of numbers
Maximum	Max	Returns the larger of the specified set of numbers
Round	Round	Returns the number nearest the specified value
Square Root	Sqrt	Returns the square root of the specified number
Sine	Sin	Returns the sine of the specified number
Cosine	Cos	Returns the cosine of the specified number
Tangent	Tan	Returns the tangent of the specified number
Inverse Tangent2	Atan2	Returns the angle whose tangent is the quotient of two specified numbers
Natural Logarithm	Ln	Returns the natural logarithm of the specified number
Common Logarithm	Log	Returns the base 10 logarithm of the specified number
Derivative	Slope	Measures how the specified function changes as its input changes

The Average, Minimum, and Maximum functions can accept multiple datasets, as shown here:

Avg(dataset1; dataset2; dataset3)

Tips and Tricks

The function calculation is repeated using the Y-Axis Value(s) for each X-Axis point. This creates a new set of Y-Axis Values (the Calculated Dataset). See the example below.

Example

If you have two datasets, generated by measuring the Motor Rotations for the motors on Port B and Port C every 10 seconds for 30 seconds, the datasets may contain the following data:

	0 seconds	10 seconds	20 seconds	30 seconds
Motor Rotations, Port B	0	1	3	4
Motor Rotations, Port C	0	2	5	7

Using the Average, Add and Multiply functions on the two datasets will generate the following Calculated Datasets:

	10 seconds	20 seconds	30 seconds
Average Motor Rotations	1.5	4	5.5
Motor Rotations, Port B + Motor Rotations, Port C	3	8	11
Motor Rotations, Port B * 1.5	1.5	4.5	6

Datasets

This list shows the Datasets available for use in the Dataset Calculation. Click on a Dataset from this list to automatically insert it into the Formula Field.