QCPRange Class Reference

Represents the range an axis is encompassing. More...

#include <qcustomplot.h>

Public Member Functions
	QCPRange ()
	QCPRange (double lower, double upper)
double	size () const
double	center () const
void	normalize ()
QCPRange	sanitizedForLogScale () const
QCPRange	sanitizedForLinScale () const

Static Public Member Functions
static bool	validRange (double lower, double upper)
static bool	validRange (const QCPRange &range)

Public Attributes
double	lower
double	upper

Static Public Attributes
static const double	minRange = 1e-280
static const double	maxRange = 1e250

Detailed Description

Represents the range an axis is encompassing.

contains a lower and upper double value and provides convenience input, output and modification functions.

See also

QCPAxis::setRange

Definition at line 491 of file qcustomplot.h.

Constructor & Destructor Documentation

QCPRange() [1/2]

QCPRange::QCPRange

(

)

Constructs a range with lower and upper set to zero.

Definition at line 2331 of file qcustomplot.cc.

                   :
  lower(0),
  upper(0)
{
}

QCPRange() [2/2]

QCPRange::QCPRange	(	double	lower,
		double	upper
	)

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Constructs a range with the specified lower and upper values.

Definition at line 2340 of file qcustomplot.cc.

{
  this->lower = lower;
  this->upper = upper;
}

Member Function Documentation

center()

double QCPRange::center

(

)

const

Returns the center of the range, i.e. (upper+lower)*0.5

Definition at line 2357 of file qcustomplot.cc.

{
  return (upper+lower)*0.5;
}

normalize()

void QCPRange::normalize

(

)

Makes sure lower is numerically smaller than upper. If this is not the case, the values are swapped.

Definition at line 2366 of file qcustomplot.cc.

{
  if (lower > upper)
    qSwap(lower, upper);
}

sanitizedForLinScale()

QCPRange QCPRange::sanitizedForLinScale

(

)

const

Returns a sanitized version of the range. Sanitized means for linear scales, that lower will always be numerically smaller (or equal) to upper.

Definition at line 2433 of file qcustomplot.cc.

{
  QCPRange sanitizedRange(lower, upper);
  sanitizedRange.normalize();
  return sanitizedRange;
}

sanitizedForLogScale()

QCPRange QCPRange::sanitizedForLogScale

(

)

const

Returns a sanitized version of the range. Sanitized means for logarithmic scales, that the range won't span the positive and negative sign domain, i.e. contain zero. Further lower will always be numerically smaller (or equal) to upper.

If the original range does span positive and negative sign domains or contains zero, the returned range will try to approximate the original range as good as possible. If the positive interval of the original range is wider than the negative interval, the returned range will only contain the positive interval, with lower bound set to rangeFac or rangeFac *upper, whichever is closer to zero. Same procedure is used if the negative interval is wider than the positive interval, this time by changing the upper bound.

Definition at line 2384 of file qcustomplot.cc.

{
  double rangeFac = 1e-3;
  QCPRange sanitizedRange(lower, upper);
  sanitizedRange.normalize();
  // can't have range spanning negative and positive values in log plot, so change range to fix it
  //if (qFuzzyCompare(sanitizedRange.lower+1, 1) && !qFuzzyCompare(sanitizedRange.upper+1, 1))
  if (sanitizedRange.lower == 0.0 && sanitizedRange.upper != 0.0)
  {
    // case lower is 0
    if (rangeFac < sanitizedRange.upper*rangeFac)
      sanitizedRange.lower = rangeFac;
    else
      sanitizedRange.lower = sanitizedRange.upper*rangeFac;
  } //else if (!qFuzzyCompare(lower+1, 1) && qFuzzyCompare(upper+1, 1))
  else if (sanitizedRange.lower != 0.0 && sanitizedRange.upper == 0.0)
  {
    // case upper is 0
    if (-rangeFac > sanitizedRange.lower*rangeFac)
      sanitizedRange.upper = -rangeFac;
    else
      sanitizedRange.upper = sanitizedRange.lower*rangeFac;
  } else if (sanitizedRange.lower < 0 && sanitizedRange.upper > 0)
  {
    // find out whether negative or positive interval is wider to decide which sign domain will be chosen
    if (-sanitizedRange.lower > sanitizedRange.upper)
    {
      // negative is wider, do same as in case upper is 0
      if (-rangeFac > sanitizedRange.lower*rangeFac)
        sanitizedRange.upper = -rangeFac;
      else
        sanitizedRange.upper = sanitizedRange.lower*rangeFac;
    } else
    {
      // positive is wider, do same as in case lower is 0
      if (rangeFac < sanitizedRange.upper*rangeFac)
        sanitizedRange.lower = rangeFac;
      else
        sanitizedRange.lower = sanitizedRange.upper*rangeFac;
    }
  }
  // due to normalization, case lower>0 && upper<0 should never occur, because that implies upper<lower
  return sanitizedRange;
}

size()

double QCPRange::size

(

)

const

Returns the size of the range, i.e. upper-lower

Definition at line 2349 of file qcustomplot.cc.

{
  return upper-lower;
}

validRange() [1/2]

bool QCPRange::validRange ( double  lower, double  upper  )

static

Checks, whether the specified range is within valid bounds, which are defined as QCPRange::maxRange and QCPRange::minRange. A valid range means:

• range bounds within -maxRange and maxRange
• range size above minRange
• range size below maxRange

Definition at line 2448 of file qcustomplot.cc.

{
  /*
  return (lower > -maxRange &&
          upper < maxRange &&
          fabs(lower-upper) > minRange &&
          (lower < -minRange || lower > minRange) &&
          (upper < -minRange || upper > minRange));
          */
  return (lower > -maxRange &&
          upper < maxRange &&
          fabs(lower-upper) > minRange &&
          fabs(lower-upper) < maxRange);
}

validRange() [2/2]

bool QCPRange::validRange ( const QCPRange &  range )

static

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. Checks, whether the specified range is within valid bounds, which are defined as QCPRange::maxRange and QCPRange::minRange. A valid range means:

• range bounds within -maxRange and maxRange
• range size above minRange
• range size below maxRange

Definition at line 2472 of file qcustomplot.cc.

{
  /*
  return (range.lower > -maxRange &&
          range.upper < maxRange &&
          fabs(range.lower-range.upper) > minRange &&
          fabs(range.lower-range.upper) < maxRange &&
          (range.lower < -minRange || range.lower > minRange) &&
          (range.upper < -minRange || range.upper > minRange));
          */
  return (range.lower > -maxRange &&
          range.upper < maxRange &&
          fabs(range.lower-range.upper) > minRange &&
          fabs(range.lower-range.upper) < maxRange);
}

Member Data Documentation

lower

double QCPRange::lower

Definition at line 494 of file qcustomplot.h.

maxRange

const double QCPRange::maxRange = 1e250

static

Maximum values (negative and positive) the range will accept in range-changing functions. Larger absolute values would cause errors due to the 11-bit exponent of double precision numbers, corresponding to a maximum magnitude of roughly 1e308. Since the number of planck-volumes in the entire visible universe is only ~1e183, this should be enough.

See also

validRange, minRange

Definition at line 509 of file qcustomplot.h.

minRange

const double QCPRange::minRange = 1e-280

static

Minimum range size (upper - lower) the range changing functions will accept. Smaller intervals would cause errors due to the 11-bit exponent of double precision numbers, corresponding to a minimum magnitude of roughly 1e-308.

See also

validRange, maxRange

Definition at line 508 of file qcustomplot.h.

upper

double QCPRange::upper

Definition at line 494 of file qcustomplot.h.

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The documentation for this class was generated from the following files:

• /build/rock-master-18.09-gui-rock-widget-collection-0.20180124/src/plot2d/qcustomplot.h
• /build/rock-master-18.09-gui-rock-widget-collection-0.20180124/src/plot2d/qcustomplot.cc