histogram/doc/concepts/IntervalAxis.qbk
Hans Dembinski df647cf959
update copyright (#55)
* add missing copyright notices
* workaround for xml_iarchive bug to handle XML with comments
* fixing min/max according to boost guidelines
2019-08-19 16:53:27 +02:00

84 lines
3.3 KiB
Plaintext

[/
Copyright Hans Dembinski 2018 - 2019.
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE_1_0.txt or copy at
https://www.boost.org/LICENSE_1_0.txt)
]
[section:IntervalAxis IntervalAxis]
A [*IntervalAxis] is one of two optional refinements of the [link histogram.concepts.Axis [*Axis]] concept, the other one is the [link histogram.concepts.DiscreteAxis DiscreteAxis]. It is for ordered values that form intervals with a well-defined lower and upper edge, and a center. Each bin represents an interval of values.
[heading Associated Types]
* [link histogram.concepts.Axis [*Axis]]
* [link histogram.concepts.DiscreteAxis [*DiscreteAxis]]
[heading Requirements]
* `A` is a type meeting the requirements of [*IntervalAxis]
* `a` is a value of type `A`
* `V` is the type accepted for conversion into an index
* `B` is the type that represents the bin interval
* `v` is a value of type `V`
* `i` is a value of type [headerref boost/histogram/fwd.hpp `boost::histogram::axis::index_type`]
* `j` is a value of type [headerref boost/histogram/fwd.hpp `boost::histogram::axis::real_index_type`]
* `AxisIter` is an /RandomAccessIterator/ over the bins of `A`
* `ReAxisIter` is a reverse /RandomAccessIterator/ over the bins of `A`
[table Valid expressions
[[Expression] [Returns] [Semantics, Pre/Post-conditions]]
[
[`a.value(i)`]
[`V`]
[
Const member function which maps an index to a value. The mapping must be injective: each index must be uniquely mapped to one value. The result of `a.value(a.index(v))` should agree to very high precision with `v` (the mapping may not be exact due to the finite precision of floating point computations). The return value may be a const reference, if the lifetime of the referred object is equal to the lifetime of the axis. `a.value(j)` is expected to return the lower edge of the bin, `a.value(j+1)` the upper edge, and `a.value(j + 0.5)` the center.
]
]
[
[`a.bin(i)`]
[`B`]
[
Const member function which returns an instance that represents the current bin. Nothing about the type is required, but it is recommended that the type has the methods `B::lower()`, `B::upper()`, and `B::center()` similar to the types used by the builtin axis models. The return value may be a const reference, if the lifetime of the referred object is equal to the lifetime of the axis.
]
]
[
[`s.begin()`]
[`AxisIter`]
[
Const member function which return an iterator to the bin with index `0`.
]
]
[
[`s.end()`]
[`AxisIter`]
[
Const member function which returns an iterator to the bin with index `s.size()`.
]
]
[
[`s.rbegin()`]
[`ReAxisIter`]
[
Const member function which return a reverse iterator to the bin with index `s.size()-1`.
]
]
[
[`s.rend()`]
[`ReAxisIter`]
[
Const member function which returns an iterator to the bin with index `-1`.
]
]
]
[tip The complete iterator interface can be added to a user-defined axis which implements `a.bin(i)` by inheriting from the [classref boost::histogram::axis::iterator_mixin iterator_mixin].]
[heading Models]
* [classref boost::histogram::axis::regular]
* [classref boost::histogram::axis::variable]
* [classref boost::histogram::axis::integer], if first template parameter is a floating point type
[endsect]