<numeric>

Include the STL standard header <numeric> to define several template functions useful for computing numeric values. The descriptions of these templates employ a number of conventions common to all algorithms.

namespace std {
template<class InIt, class Ty>
    Ty accumulate(InIt first, InIt last, Ty val);
template<class InIt, class Ty, class Fn2>
    Ty accumulate(InIt first, InIt last, Ty val, Fn2 func);
template<class InIt1, class InIt2, class Ty>
    Ty inner_product(InIt1 first1, InIt1 last1,
        Init2 first2, Ty val);
template<class InIt1, class InIt2, class Ty,
    class Fn21, class Fn22>
    Ty inner_product(InIt1 first1, InIt1 last1,
        Init2 first2, Ty val, Fn21 func1, Fn22 func2);
template<class InIt, class OutIt>
    OutIt partial_sum(InIt first, InIt last,
        OutIt result);
template<class InIt, class OutIt, class Fn2>
    OutIt partial_sum(InIt first, InIt last,
        OutIt result, Fn2 func);
template<class InIt, class OutIt>
    OutIt adjacent_difference(InIt first, InIt last,
        OutIt result);
template<class InIt, class OutIt, class Fn2>
    OutIt adjacent_difference(InIt first, InIt last,
        OutIt result, Fn2 func);
    };

accumulate

template<class InIt, class Ty>
    Ty accumulate(InIt first, InIt last, Ty val);
template<class InIt, class Ty, class Fn2>
    Ty accumulate(InIt first, InIt last, Ty val, Fn2 func);

The first template function repeatedly replaces val with val + *I, for each value of the InIt iterator I in the interval [first, last). It then returns val.

The second template function repeatedly replaces val with func(val, *I), for each value of the InIt iterator I in the interval [first, last). It then returns val.

adjacent_difference

template<class InIt, class OutIt>
    OutIt adjacent_difference(InIt first, InIt last,
        OutIt result);
template<class InIt, class OutIt, class Fn2>
    OutIt adjacent_difference(InIt first, InIt last,
        OutIt result, Fn2 func);

The first template function stores successive values beginning at result, for each value of the InIt iterator I in the interval [first, last). The first value val stored (if any) is *I. Each subsequent value stored is *I - val, and val is replaced by *I. The function returns result incremented last - first times.

The second template function stores successive values beginning at result, for each value of the InIt iterator I in the interval [first, last). The first value val stored (if any) is *I. Each subsequent value stored is func(*I, val), and val is replaced by *I. The function returns result incremented last - first times.

inner_product

template<class InIt1, class InIt2, class Ty>
    Ty inner_product(InIt1 first1, InIt1 last1,
        Init2 first2, Ty val);
template<class InIt1, class InIt2, class Ty,
    class Fn21, class Fn22>
    Ty inner_product(InIt1 first1, InIt1 last1,
        Init2 first2, Ty val, Fn21 func1, Fn22 func2);

The first template function repeatedly replaces val with val + (*I1 * *I2), for each value of the InIt1 iterator I1 in the interval [first1, last2). In each case, the InIt2 iterator I2 equals first2 + (I1 - first1). The function returns val.

The second template function repeatedly replaces val with func1(val, func2(*I1, *I2)), for each value of the InIt1 iterator I1 in the interval [first1, last2). In each case, the InIt2 iterator I2 equals first2 + (I1 - first1). The function returns val.

partial_sum

template<class InIt, class OutIt>
    OutIt partial_sum(InIt first, InIt last,
        OutIt result);
template<class InIt, class OutIt, class Fn2>
    OutIt partial_sum(InIt first, InIt last,
        OutIt result, Fn2 func);

The first template function stores successive values beginning at result, for each value of the InIt iterator I in the interval [first, last). The first value val stored (if any) is *I. Each subsequent value val stored is val + *I. The function returns result incremented last - first times.

The second template function stores successive values beginning at result, for each value of the InIt iterator I in the interval [first, last). The first value val stored (if any) is *I. Each subsequent value val stored is func(val, *I). The function returns result incremented last - first times.

See also the Table of Contents and the Index.

Copyright © 1994-2002 by P.J. Plauger. Portions derived from work copyright © 1994 by Hewlett-Packard Company. All rights reserved.