Function differenceFromFixed

differenceFromFixed(
initial: number,
kind?: DifferenceKind,
): (value: number) => number
Returns the difference from the initial value. Defaults to absolute difference.
```
const rel = differenceFromFixed(100);
rel(100); // 0
rel(150); // 50
rel(50);  // 50
```
'numerical' gives sign:
```
const rel = differenceFromFixed(100, `numerical`);
rel(100); // 0
rel(150); // 50
rel(50); // -50
```
'relative' gives proportion to initial
```
const rel = differenceFromFixed(100, `relative`);
rel(100); // 0
rel(150); // 0.5
rel(10);  // 0.90
```
Using 'relativeSigned', we get negative relative result when value is below the initial value.

Use differenceFromLast to compare against the last value, rather than the same fixed value.
Parameters
- initial: number
  Value to compare against
- kind: DifferenceKind = ...
Returns (value: number) => number
Difference from initial value