etl/docs/maths/rescale.md

title
rescale

{{< callout type="info">}} Header: rescale.h
Since: 20.9.0
{{< /callout >}}

Rescales an input range.

template <typename TInput, typename TOutput>
class rescale : public etl::unary_function<TOutput, TInput>

TInput The input data type. TCompare The functor type used to compare values to the threshold. The default is etl::less.

---

rescale (TInput  input_min_value,
         TInput  input_max_value,
         TOutput output_min_value,
         TOutput output_max_value) 

Description
Sets the rescale limits.

---

TOutput operator()(TInput value) const

Description
Rescale a value.

Example

std::array<char, 10> input = 
{ 
  10, 11, 12, 13, 14, 15, 16, 17, 18, 19
};

std::array<int, 10> output;

etl::rescale<char, int> rescale(10, 19, 40000, 41900);

std::transform(input.begin(), input.end(), output.begin(), rescale);

// output = 40000, 40211, 40422, 40633, 40844, 41055, 41266, 41477, 41688, 41900