Module: qcurve.cpp

/*
 * QCurve - curves
 * NOTES:
 * - Generated by mkclass
 * BUGS:
 * - Resize array loses information
 * 15-09-00: Created! (based on class CMSpline)
 * (C) MarketGraph/RvG
 */

#include <qlib/curve.h>
#include <math.h>
#include <qlib/debug.h>
DEBUG_ENABLE

#define DEF_PTS     50          // Starting point

#undef  DBG_CLASS
#define DBG_CLASS "QCurve"

QCurve::QCurve()
{
  DBG_C("ctor")

  // Axes
  xName="X-axis";
  yName="Y-axis";
  xSteps=ySteps=20;
  xMin=yMin=0;
  xMax=yMax=100;

  points=0;
  p=0;
  AllocatePoints(DEF_PTS);
}

QCurve::~QCurve()
{
  DBG_C("dtor")
  if(p)qfree(p);
}

void QCurve::AllocatePoints(int n)
{
  if(p)qfree(p);
  pointsAllocated=n;
  p=(QCurvePoint*)qcalloc(pointsAllocated*sizeof(QCurvePoint));
  if(!p)qerr("QCurve: out of memory for point array (%d pts)\n",points);
}

void QCurve::Reset()
{
  points=0;
}

QCurvePoint *QCurve::GetPoint(int n)
// Returns point structure #n
{
  if(points==0)return 0;
  if(n<0)return 0;
  if(n>=points)return 0;
  return &p[n];
}

int QCurve::FindRightPoint(qcfloat x)
// Returns point closest to the right of 'x'
// Returns 'points' if 'x' is more to the right than any of the points
// Could use binary search
{
  int i;
  for(i=0;i<points;i++)
  {
    if(p[i].x>x)break;
  }
  return i;
}

int QCurve::AddPoint(qcfloat x,qcfloat y,int type)
// Add a point to the curve; insert where necessary
// Returns point index where it was inserted
{
  int i,insertIndex;
  if(points+1>pointsAllocated)
  { // Resize array
    AllocatePoints(points+50);
  }
  // Find place at which to insert new point
  insertIndex=FindRightPoint(x);
  // Shift array to accomodate new point
  for(i=points;i>insertIndex;i--)
  { p[i]=p[i-1];
  }
  // Put new point in
  p[insertIndex].x=x;
  p[insertIndex].y=y;
  p[insertIndex].type=type;
  points++;
  return insertIndex;
}
void QCurve::ModifyPoint(int n,qcfloat x,qcfloat y)
// Rethink the x/y location
{
  if(n<0)return;
  if(n>=points)return;
  if(n>0)
  {
    // Bounce at previous entry
    if(x<p[n-1].x)return;
  }
  if(n<points-1)
  { // Bounce at next entry
    if(x>p[n+1].x)return;
  }
  // Set new coordinates
  p[n].x=x;
  p[n].y=y;
}

void QCurve::RemovePoint(int n)
{
  if(points==0)return;
  if(n<0)return;
  if(n>=points)return;
  // Shift array
  int i;
  for(i=n;i<points-1;i++)
  { p[i]=p[i+1];
  }
  points--;
}
void QCurve::SetPointType(int n,int type)
{
  if(n<0)return;
  if(n>=points)return;
  p[n].type=type;
}

qcfloat QCurve::GetValue(qcfloat x)
// For a given x, approximate the y
{
//qdbg("QCurve(this=%p): GetValue(%f); points=%d\n",this,x,points);
  // Any points at all?
  if(!points)return 0.0;

  int rp;
  double dx,dy;

  // Find right point of 'x'
  rp=FindRightPoint(x);
//qdbg("QCurve: GetValue(%f); rp=%d\n",x,rp);
  if(rp==0)
  { // To the left of the graph; use initial value
    return p[0].y;
  } else if(rp==points)
  { // To the right of the graph; use last value
    return p[points-1].y;
  }
  // Interpolate between 'rp' and previous point
  dx=p[rp].x-p[rp-1].x;
  dy=p[rp].y-p[rp-1].y;
  return (x-p[rp-1].x)/dx*dy+p[rp-1].y;
}
int QCurve::GetPointType(int n)
{
  if(n<0)return 0;
  if(n>=points)return 0;
  return p[n].type;
}

/************
* LOAD/SAVE *
************/
bool QCurve::Load(QInfo *info,cstring path)
{
  QASSERT_VALID()
  DBG_C("Load")
  DBG_ARG_P(info)
  DBG_ARG_S(path)

  char buf[128];

  sprintf(buf,"%s.xname",path);
  info->GetString(buf,xName);
  sprintf(buf,"%s.yname",path);
  info->GetString(buf,yName);
  sprintf(buf,"%s.xsteps",path);
  xSteps=info->GetInt(buf);
  sprintf(buf,"%s.ysteps",path);
  ySteps=info->GetInt(buf);

  sprintf(buf,"%s.xmin",path);
  xMin=info->GetInt(buf);
  sprintf(buf,"%s.ymin",path);
  yMin=info->GetInt(buf);
  sprintf(buf,"%s.xmax",path);
  xMax=info->GetInt(buf);
  sprintf(buf,"%s.ymax",path);
  yMax=info->GetInt(buf);

  // Points
  sprintf(buf,"%s.points",path);
  points=info->GetInt(buf);
  AllocatePoints(points+DEF_PTS);
  for(int i=0;i<points;i++)
  {
    sprintf(buf,"%s.point%d.x",path,i);
    p[i].x=info->GetFloat(buf);
    sprintf(buf,"%s.point%d.y",path,i);
    p[i].y=info->GetFloat(buf);
    sprintf(buf,"%s.point%d.type",path,i);
    p[i].type=info->GetInt(buf);
  }

  return TRUE;
}
bool QCurve::Save(QInfo *info,cstring path)
{
  char buf[128];

  sprintf(buf,"%s.xname",path);
  info->SetString(buf,xName);
  sprintf(buf,"%s.yname",path);
  info->SetString(buf,yName);
  sprintf(buf,"%s.xsteps",path);
  info->SetInt(buf,xSteps);
  sprintf(buf,"%s.ysteps",path);
  info->SetInt(buf,ySteps);

  // Min/max
  sprintf(buf,"%s.xmin",path);
  info->SetInt(buf,xMin);
  sprintf(buf,"%s.ymin",path);
  info->SetInt(buf,yMin);
  sprintf(buf,"%s.xmax",path);
  info->SetInt(buf,xMax);
  sprintf(buf,"%s.ymax",path);
  info->SetInt(buf,yMax);

  // The points
  sprintf(buf,"%s.points",path);
  info->SetInt(buf,points);
  for(int i=0;i<points;i++)
  {
    sprintf(buf,"%s.point%d.x",path,i);
    info->SetFloat(buf,p[i].x);
    sprintf(buf,"%s.point%d.y",path,i);
    info->SetFloat(buf,p[i].y);
    if(p[i].type!=QCurvePoint::T_LINEAR)
    {
      sprintf(buf,"%s.point%d.type",path,i);
      info->SetInt(buf,p[i].type);
    }
  }

  // Flush
  info->Write();
  return TRUE;
}