etl/docs/maths/standard_deviation.md

title
standard_deviation

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

template <bool Standard_Deviation_Type, typename TInput, typename TCalc = TInput>
class standard_deviation  : public etl::unary_function<TInput, void> 

Standard_Deviation_Type Population or Sample.
TInput The input data type.
TCalc The type to use for internal calculations. By default, equal to TInput.

Enumeration

standard_deviation_type
etl::standard_deviation_type::Sample     
etl::standard_deviation_type::Population 

---

standard_deviation()

Description
Default constructor.

---

template <typename TIterator>
standard_deviation(TIterator first, TIterator last)

Description
Construct from an iterator range.

---

void add(TInput value1)

Description
Add a value.

---

template <typename TIterator>
void add(TIterator first, TIterator last)

Description
Add a range of values.

---

void operator()(TInput value)

Description
Add a values.

---

template <typename TIterator>
void operator()(TIterator first, TIterator last)

Description
Add a range of values.

---

double get_standard_deviation() const

Return
The calculated standard deviation for the data.

---

double get_variance() const

Return
The calculated variance for the data.

---

operator double() const

Return
The calculated standard deviation for the data.

---

size_t count() const

Description
Get the total number added entries.

---

void clear()

Description
Clear the standard deviation.

Example

std::array<char, 10> input
{
  0, 1, 2, 3, 4, 5, 6, 7, 8, 9
};

etl::standard_deviation<etl::standard_deviation_type::Population, char, int32_t> 
    standard_deviation(input.begin(), input.end());

double standard_deviation_result;
double variance_result;

standard_deviation_result = standard_deviation; // standard_deviation_result  == 2.87
variance_result = standard_deviation.get_variance(); // variance_result  == 8.25