Direct copy makes no transformations. It just copies the point.

Linear Transformation lets you multiply by one value and add another value, such as in the equation y = mx + b where the destination point is y, the source point is x, the multiply by value is m, and the then add value is b. For example to transform a Celsius source point to a Fahrenheit destination point, you would multiply by 1.8 and add 32, or

Fahrenheit = (1.8 X Celsius) + 32

If you have selected the Inverse direction for a transformation, you will get the inverse of the transformation. In this example, you would get a conversion from Fahrenheit to Celsius, or the results of this equation:

Celsius = (Fahrenheit - 32) / 1.8

As an alternative to entering transformation values, the DataHub program also offers Linear Range Mapping.

Linear Range Mapping lets you enter a range for the source and destination, and the DataHub program automatically calculates the corresponding linear transformation. For example, to create the same Fahrenheit to Celsius transformation, you could use the defaults of 0 and 100 for the Min and Max of the source point. Then you would enter 32 and 212 for the Min and Max of the destination point. As soon as you make these entries, the correct values get entered automatically in the Linear Transformation.

When you use linear range mapping, you can limit the transformed value to the maximum and minimum by checking the Clamp boxes. The clamps get applied to the point being changed, i.e.. to the destination point for forward direction, to the source point for inverse direction, and to both points for bidirectional bridges.