PlotMM::ScaleDiv Class Reference

List of all members.

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Detailed Description

A class for building scale divisions.

The ScaleDiv class can build linear and logarithmic scale divisions for specified intervals. It uses an adjustable algorithm to generate the major and minor step widths automatically. A scale division has a minimum value, a maximum value, a vector of major marks, and a vector of minor marks.

Warning:

ScaleDiv uses implicit sharing for the mark vectors.

Example

To build a logarithmic scale division from 0.01 to 1000 and print out the major and minor marks.

#include <plotmm/scalediv.h>
#include <iostream.h>

main()
{
  int i,k;
  PlotMM::ScaleDiv sd;

  sd.rebuild(0.01, 1000, 10, 10, TRUE, 0.0);

  k=0;
  for (i=0;i<sd.maj_count();i++)
  {
    while(k < sd.min_count())
    {
      if (sd.min_mark(k) < sd.maj_mark(i))
      {
        cout << " - " << sd.min_mark(i) << "\n";
    k++;
      }
      else
        break;
    }
    cout << "-- " << sd.maj_mark(i) << "\n";
  }
  while(k < sd.min_count())
  {
    cout << " - " << sd.min_mark(i) << "\n";
    k++;
  }
}

Public Member Functions
	ScaleDiv ()
int	operator== (const ScaleDiv &s) const
int	operator!= (const ScaleDiv &s) const
double	low_bound () const
double	high_bound () const
uint	min_count () const
uint	maj_count () const
bool	log_scale () const
double	maj_mark (int i) const
double	min_mark (int i) const
double	maj_step () const
void	reset ()
bool	rebuild (double lBound, double hBound, int maxMaj, int maxMin, bool log, double step=0.0, bool ascend=true)

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Constructor & Destructor Documentation

ScaleDiv::ScaleDiv (   )

Construct a ScaleDiv instance.

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Member Function Documentation

double PlotMM::ScaleDiv::high_bound (   )  const

Returns: right bound See also: ScaleDiv::rebuild

bool PlotMM::ScaleDiv::log_scale (   )  const

Returns: TRUE id ths scale div is logarithmic See also: ScaleDiv::rebuild

double PlotMM::ScaleDiv::low_bound (   )  const

Returns: left bound See also: ScaleDiv::rebuild

uint PlotMM::ScaleDiv::maj_count (   )  const

Returns: major mark count See also: ScaleDiv::rebuild

double PlotMM::ScaleDiv::maj_mark (  int  i  )  const

Return major mark at position i.

double PlotMM::ScaleDiv::maj_step (   )  const

Returns: major step size See also: ScaleDiv::rebuild

uint PlotMM::ScaleDiv::min_count (   )  const

Returns: minor mark count See also: ScaleDiv::rebuild

double PlotMM::ScaleDiv::min_mark (  int  i  )  const

Return minor mark at position i.

int ScaleDiv::operator!= (  const ScaleDiv &  s  )  const

Inequality. Returns: true if this instance is not equal to s

int ScaleDiv::operator== (  const ScaleDiv &  s  )  const

Equality operator. Returns: true if this instance is equal to s

bool ScaleDiv::rebuild (  double  x1, double  x2, int  maxMajSteps, int  maxMinSteps, bool  log, double  step = 0.0, bool  ascend = true )

Build a scale width major and minor divisions If no fixed step width is specified or if it is set to 0, the major step width will be calculated automatically according to the the value of maxMajSteps. The maxMajSteps parameter has no effect if a fixed step size is specified. The minor step width is always calculated automatically. If the step width is to be calculated automatically, the algorithm tries to find reasonable values fitting into the scheme {1,2,5}*10^n with an integer number n for linear scales. For logarithmic scales, there are three different cases If the major step width is one decade, the minor marks will fit into one of the schemes {1,2,...9}, {2,4,6,8}, {2,5} or {5}, depending on the maxMinSteps parameter. If the major step size spans more than one decade, the minor step size will be {1,2,5}*10^n decades with a natural number n. If the whole range is less than one decade, a linear scale division will be built. Parameters: x1  first boundary value x2  second boundary value maxMajSteps  max. number of major step intervals maxMinSteps  max. number of minor step intervals log  logarithmic division (true/false) step  fixed major step width. Defaults to 0.0. ascend  if true, sort in ascending order from min(x1, x2) to max(x1, x2). If false, sort in the direction from x1 to x2. Defaults to true. Returns: True if the arrays have been allocated successfully. Warning: For logarithmic scales, the step width is measured in decades.

void ScaleDiv::reset (   )

Detach the shared data and set everything to zero.

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