# QwtInterval Class Reference

A class representing an interval. More...

`#include <qwt_interval.h>`

List of all members.

## Public Types

enum | BorderFlag { IncludeBorders = 0x00, ExcludeMinimum = 0x01, ExcludeMaximum = 0x02, ExcludeBorders = ExcludeMinimum | ExcludeMaximum }
typedef QFlags< BorderFlag > | BorderFlags

## Public Member Functions

BorderFlags | borderFlags () const
bool | contains (double value) const
QwtInterval | extend (double value) const
QwtInterval | intersect (const QwtInterval &) const
bool | intersects (const QwtInterval &) const
void | invalidate ()
QwtInterval | inverted () const
bool | isNull () const
bool | isValid () const
QwtInterval | limited (double minValue, double maxValue) const
double | maxValue () const
double | minValue () const
QwtInterval | normalized () const
bool | operator!= (const QwtInterval &) const
QwtInterval | operator& (const QwtInterval &) const
QwtInterval & | operator&= (const QwtInterval &)
bool | operator== (const QwtInterval &) const
QwtInterval | operator| (double) const
QwtInterval | operator| (const QwtInterval &) const
QwtInterval & | operator|= (double)
QwtInterval & | operator|= (const QwtInterval &)
| QwtInterval (double minValue, double maxValue, BorderFlags=IncludeBorders)
| QwtInterval ()
void | setBorderFlags (BorderFlags)
void | setInterval (double minValue, double maxValue, BorderFlags=IncludeBorders)
void | setMaxValue (double)
void | setMinValue (double)
QwtInterval | symmetrize (double value) const
QwtInterval | unite (const QwtInterval &) const
double | width () const

## Detailed Description

A class representing an interval.

The interval is represented by 2 doubles, the lower and the upper limit.

## Member Typedef Documentation

typedef QFlags<BorderFlag> QwtInterval::BorderFlags

Border flags.

## Member Enumeration Documentation

enum QwtInterval::BorderFlag

Flag indicating if a border is included or excluded

See also:
  setBorderFlags(), borderFlags()

Enumerator:

  IncludeBorders | Min/Max values are inside the interval.
  ExcludeMinimum | Min value is not included in the interval.
  ExcludeMaximum | Max value is not included in the interval.
  ExcludeBorders | Min/Max values are not included in the interval.

## Constructor & Destructor Documentation

QwtInterval::QwtInterval | ( |  | ) | `[inline]`

Default Constructor.

Creates an invalid interval [0.0, -1.0]

See also:
  setInterval(), isValid()

QwtInterval::QwtInterval | ( | double | minValue,
|  | double | maxValue,
|  | BorderFlags | borderFlags = `IncludeBorders`
| ) |  | `[inline]`

Constructor

Build an interval with from min/max values

Parameters:

  minValue | Minimum value
  maxValue | Maximum value
  borderFlags | Include/Exclude borders

## Member Function Documentation

QwtInterval::BorderFlags QwtInterval::borderFlags | ( |  | ) | const`[inline]`

Returns:
  Border flags

See also:
  setBorderFlags()

bool QwtInterval::contains | ( | double | value | ) | const

Test if a value is inside an interval

Parameters:

  value | Value

Returns:
  true, if value >= minValue() && value <= maxValue()

QwtInterval QwtInterval::extend | ( | double | value | ) | const

Extend the interval

If value is below minValue, value becomes the lower limit. If value is above maxValue, value becomes the upper limit.

extend has no effect for invalid intervals

Parameters:

  value | Value

See also:
  isValid()

QwtInterval QwtInterval::intersect | ( | const QwtInterval & | other | ) | const

Intersect 2 intervals.

bool QwtInterval::intersects | ( | const QwtInterval & | other | ) | const

Test if two intervals overlap

void QwtInterval::invalidate | ( |  | ) | `[inline]`

Invalidate the interval

The limits are set to interval [0.0, -1.0]

See also:
  isValid()

QwtInterval QwtInterval::inverted | ( |  | ) | const

Invert the limits of the interval

Returns:
  Inverted interval

See also:
  normalized()

bool QwtInterval::isNull | ( |  | ) | const`[inline]`

Returns:
  true, if isValid() && (minValue() >= maxValue())

bool QwtInterval::isValid | ( |  | ) | const`[inline]`

A interval is valid when minValue() <= maxValue(). In case of QwtInterval::ExcludeBorders it is true when minValue() < maxValue()

QwtInterval QwtInterval::limited | ( | double | lowerBound,
|  | double | upperBound
| ) |  | const

Limit the interval, keeping the border modes

Parameters:

  lowerBound | Lower limit
  upperBound | Upper limit

Returns:
  Limited interval

double QwtInterval::maxValue | ( |  | ) | const`[inline]`

Returns:
  Upper limit of the interval

double QwtInterval::minValue | ( |  | ) | const`[inline]`

Returns:
  Lower limit of the interval

QwtInterval QwtInterval::normalized | ( |  | ) | const

Normalize the limits of the interval.

If maxValue() < minValue() the limits will be inverted.

Returns:
  Normalized interval

See also:
  isValid(), inverted()

bool QwtInterval::operator!= | ( | const QwtInterval & | other | ) | const`[inline]`

Compare two intervals.

QwtInterval QwtInterval::operator& | ( | const QwtInterval & | interval | ) | const`[inline]`

Intersection of two intervals

See also:
  intersect()

QwtInterval & QwtInterval::operator&= | ( | const QwtInterval & | interval | ) |

Intersects this interval with the given interval.

bool QwtInterval::operator== | ( | const QwtInterval & | other | ) | const`[inline]`

Compare two intervals.

QwtInterval QwtInterval::operator| | ( | const QwtInterval & | interval | ) | const`[inline]`

Union of two intervals

See also:
  unite()

QwtInterval QwtInterval::operator| | ( | double | value | ) | const`[inline]`

Extend an interval

Parameters:

  value | Value

Returns:
  Extended interval

See also:
  extend()

QwtInterval & QwtInterval::operator|= | ( | const QwtInterval & | interval | ) |

Unites this interval with the given interval.

QwtInterval & QwtInterval::operator|= | ( | double | value | ) |

Extend an interval

Parameters:

  value | Value

Returns:
  Reference of the extended interval

See also:
  extend()

void QwtInterval::setBorderFlags | ( | BorderFlags | borderFlags | ) | `[inline]`

Change the border flags

Parameters:

  borderFlags | Or'd BorderMode flags

See also:
  borderFlags()

void QwtInterval::setInterval | ( | double | minValue,
|  | double | maxValue,
|  | BorderFlags | borderFlags = `IncludeBorders`
| ) |  | `[inline]`

Assign the limits of the interval

Parameters:

  minValue | Minimum value
  maxValue | Maximum value
  borderFlags | Include/Exclude borders

void QwtInterval::setMaxValue | ( | double | maxValue | ) | `[inline]`

Assign the upper limit of the interval

Parameters:

  maxValue | Maximum value

void QwtInterval::setMinValue | ( | double | minValue | ) | `[inline]`

Assign the lower limit of the interval

Parameters:

  minValue | Minimum value

QwtInterval QwtInterval::symmetrize | ( | double | value | ) | const

Adjust the limit that is closer to value, so that value becomes the center of the interval.

Parameters:

  value | Center

Returns:
  Interval with value as center

QwtInterval QwtInterval::unite | ( | const QwtInterval & | other | ) | const

Unite 2 intervals.

double QwtInterval::width | ( |  | ) | const`[inline]`

Return the width of an interval The width of invalid intervals is 0.0, otherwise the result is maxValue() - minValue().

See also:
  isValid()