Class QAccelPlot::Histogram¶

ClassList > QAccelPlot > Histogram

Samples counted into bins, convertible to BarSeries data.More...

#include <Histogram.hpp>

Public Properties¶

Type	Name
property QML_ANONYMOUSint	binCount Read-only: number of bins; 0 for an invalid histogram.
property qreal	binWidth Read-only: the width of every bin, or NaN when the bins are not uniform.
property QList< qreal >	edges Read-only: the `binCount` + 1 bin edges in ascending order.
property qreal	total Read-only: sum of the bin counts, the number of samples inside the edges.
property bool	uniform Read-only: true when all bins have the same width.
property QList< qreal >	values Read-only: one value per bin, a count or, after `density()` , a density.

Public Functions¶

Type	Name
std::vector< double >	barData () const Returns `binCount()` interleaved (from, to, value) bars, one per bin, for`BarSeries::setRangedData()` .
Q_INVOKABLE QVariantList	bars () const Returns one object per bin with `from` ,`to` , and`value` , for the QML`BarSeries.setData()` .
int	binCount () const Returns the number of bins; 0 for an invalid histogram.
double	binWidth () const Returns the width of every bin, or NaN when the bins are not uniform.
Q_INVOKABLE Histogram	density () const Returns a copy whose values are densities: count / ( `total()` × bin width).
const std::vector< double > &	edges () const Returns the `binCount()` + 1 bin edges in ascending order.
bool	isUniform () const Returns true when all bins have the same width.
double	total () const Returns the sum of the bin counts, the number of samples inside the edges.
const std::vector< double > &	values () const Returns one value per bin, a count or, after `density()` , a density.

Public Static Functions¶

Type	Name
std::vector< double >	decadeEdges (double min, double max) Returns the edges from min to__max at 1, 2, ..., 9 times each power of ten: the ticks of a logarithmic axis.
Histogram	fromCounts (std::vector< double > edges, std::vector< double > counts) Wraps data that is already binned: counts has one finite, non-negative value per bin between__edges .
Histogram	fromSamples (const double * samples, std::size_t sampleCount, int binCount) Counts sampleCount __samples into__binCount equal bins spanning the finite samples.
Histogram	fromSamples (const double * samples, std::size_t sampleCount, int binCount, double min, double max) Counts sampleCount __samples into__binCount equal bins from__min to__max .
Histogram	fromSamples (const double * samples, std::size_t sampleCount, std::vector< double > edges) Counts sampleCount __samples into the bins between__edges , which must be finite and strictly increasing.
Histogram	fromSamples (const float * samples, std::size_t sampleCount, int binCount) Float overload of `fromSamples` _(_samples _,_sampleCount _,_binCount ).
Histogram	fromSamples (const float * samples, std::size_t sampleCount, int binCount, double min, double max) Float overload of `fromSamples` _(_samples _,_sampleCount _,_binCount _,_min _,_max ).
Histogram	fromSamples (const float * samples, std::size_t sampleCount, std::vector< double > edges) Float overload of `fromSamples` _(_samples _,_sampleCount _,_edges ).
std::vector< double >	linearEdges (double min, double max, int binCount) Returns binCount + 1 equally spaced edges from__min to__max , or an empty vector for invalid arguments.
std::vector< double >	logEdges (double min, double max, int binCount) Returns binCount + 1 edges from__min to__max , equally spaced on a logarithmic axis.

Detailed Description¶

A bin spans from its lower edge up to, but not including, its upper edge; the last bin also includes its upper edge. NaN samples and samples outside the edges are not counted.

The functions are stateless, so a histogram can be built on a worker thread and its data passed to postData().

const auto histogram = Histogram::fromSamples(samples.data(), samples.size(), 40);
bars->setRangedData(histogram.barData(), histogram.binCount());

In QML, histograms are created by the Histogram singleton, see HistogramFactory.

See also: HistogramFactory, BarSeries

Public Properties Documentation¶

property binCount¶

Read-only: number of bins; 0 for an invalid histogram.

QML_ANONYMOUSint QAccelPlot::Histogram::binCount;

property binWidth¶

Read-only: the width of every bin, or NaN when the bins are not uniform.

qreal QAccelPlot::Histogram::binWidth;

property edges¶

Read-only: the binCount + 1 bin edges in ascending order.

QList<qreal> QAccelPlot::Histogram::edges;

property total¶

Read-only: sum of the bin counts, the number of samples inside the edges.

qreal QAccelPlot::Histogram::total;

property uniform¶

Read-only: true when all bins have the same width.

bool QAccelPlot::Histogram::uniform;

property values¶

Read-only: one value per bin, a count or, after density() , a density.

QList<qreal> QAccelPlot::Histogram::values;

Public Functions Documentation¶

function barData¶

Returns binCount() interleaved (from, to, value) bars, one per bin, forBarSeries::setRangedData() .

std::vector< double > QAccelPlot::Histogram::barData () const

function bars¶

Returns one object per bin with from ,to , andvalue , for the QMLBarSeries.setData() .

Q_INVOKABLE QVariantList QAccelPlot::Histogram::bars () const

function binCount¶

Returns the number of bins; 0 for an invalid histogram.

int QAccelPlot::Histogram::binCount () const

function binWidth¶

Returns the width of every bin, or NaN when the bins are not uniform.

double QAccelPlot::Histogram::binWidth () const

function density¶

Returns a copy whose values are densities: count / ( total() × bin width).

Q_INVOKABLE Histogram QAccelPlot::Histogram::density () const

The bin areas sum to 1, so bins of different widths and data sets of different sizes are comparable. Returns the histogram unchanged when it already holds densities.

function edges¶

Returns the binCount() + 1 bin edges in ascending order.

const std::vector< double > & QAccelPlot::Histogram::edges () const

function isUniform¶

Returns true when all bins have the same width.

bool QAccelPlot::Histogram::isUniform () const

function total¶

Returns the sum of the bin counts, the number of samples inside the edges.

double QAccelPlot::Histogram::total () const

function values¶

Returns one value per bin, a count or, after density() , a density.

const std::vector< double > & QAccelPlot::Histogram::values () const

Public Static Functions Documentation¶

function decadeEdges¶

Returns the edges from min to__max at 1, 2, ..., 9 times each power of ten: the ticks of a logarithmic axis.

static std::vector< double > QAccelPlot::Histogram::decadeEdges (
    double min,
    double max
)

min and max are the first and the last edge. min must be positive. Returns an empty vector for invalid arguments. The bins widen tenfold at each power of ten, so draw them as density().

function fromCounts¶

Wraps data that is already binned: counts has one finite, non-negative value per bin between__edges .

static Histogram QAccelPlot::Histogram::fromCounts (
    std::vector< double > edges,
    std::vector< double > counts
)

function fromSamples¶

Counts sampleCount __samples into__binCount equal bins spanning the finite samples.

static Histogram QAccelPlot::Histogram::fromSamples (
    const double * samples,
    std::size_t sampleCount,
    int binCount
)

The range is 0 to 1 without finite samples, and widens by 0.5 on each side when all samples are equal.

function fromSamples¶

Counts sampleCount __samples into__binCount equal bins from__min to__max .

static Histogram QAccelPlot::Histogram::fromSamples (
    const double * samples,
    std::size_t sampleCount,
    int binCount,
    double min,
    double max
)

function fromSamples¶

Counts sampleCount __samples into the bins between__edges , which must be finite and strictly increasing.

static Histogram QAccelPlot::Histogram::fromSamples (
    const double * samples,
    std::size_t sampleCount,
    std::vector< double > edges
)

function fromSamples¶

Float overload of fromSamples _(_samples _,_sampleCount _,_binCount ).

static Histogram QAccelPlot::Histogram::fromSamples (
    const float * samples,
    std::size_t sampleCount,
    int binCount
)

function fromSamples¶

Float overload of fromSamples _(_samples _,_sampleCount _,_binCount _,_min _,_max ).

static Histogram QAccelPlot::Histogram::fromSamples (
    const float * samples,
    std::size_t sampleCount,
    int binCount,
    double min,
    double max
)

function fromSamples¶

Float overload of fromSamples _(_samples _,_sampleCount _,_edges ).

static Histogram QAccelPlot::Histogram::fromSamples (
    const float * samples,
    std::size_t sampleCount,
    std::vector< double > edges
)

function linearEdges¶

Returns binCount + 1 equally spaced edges from__min to__max , or an empty vector for invalid arguments.

static std::vector< double > QAccelPlot::Histogram::linearEdges (
    double min,
    double max,
    int binCount
)

function logEdges¶

Returns binCount + 1 edges from__min to__max , equally spaced on a logarithmic axis.

static std::vector< double > QAccelPlot::Histogram::logEdges (
    double min,
    double max,
    int binCount
)

min must be positive. Returns an empty vector for invalid arguments.

The documentation for this class was generated from the following file QAccelPlot/src/QAccelPlot/data/Histogram.hpp