QCPChart Routines

Summary

Constructs P-Chart.

Declaration

Procedure QCPChart(Data: TVec; SampleSize: TVec; DrawVec: TVec; out CL: TSample; UCL, LCL: TVec; Confidence: TSample = 0.997);

Parameter	Description
Data	Data to be analyzed. Each value represents number of defects.
Confidence	Confidence level for upper and lower control limit. Confidence must lie in the (0,1) interval.
Samplesize	Sample size. Can be integer or vector.
DrawVec	Returns values to be drawn.
CL	Returns control Chart centerline.
UCL	Returns control Chart upper control limit.
LCL	Returns control Chart lower control limit.

Description

In this case each sample can have different size. You must store sizes in SampleSize vector. An exeption is raised if Data and SampleSize length do not match.

See Also
TQCSeries
QCNPChart
QCUChart
QCCChart

Example 1

The following code will create P chart:

  Uses StatControlCharts, MtxExp, Math387, MtxVecTee, StatSeries;
  procedure Example(Series1: TQCSeries);
  var CL, UCL, LCL : TSample;
    Data: Matrix;
    DrawVec: Vector;
  begin
    Data.LoadFromFile('data.mtx');
    QCPChart(Data,DrawVec,CL,UCL,LCL,0.05);
    // setup limit lines
    Series1.UCL := UCL;
    Series1.LCL := LCL;
    Series1.CL := CL;
    // now draw actual data
    DrawValues(DrawVec,Series1);
  end;

  #include "StatSeries.hpp"
  #include "MtxVecTee.hpp"
  #include "MtxVecCpp.h"
  #include "StatControlCharts.hpp"
  #include "Math387.hpp"
  void __fastcall Example(TQCSeries* Series1)
  {
    Vector DrawVec;
    Matrix Data;
    double cl,lcl,ucl;
    QCPChart(Data,DrawVec,cl,ucl,lcl,0.05);
    // Setup series properties
    Series1->UCL = ucl;
    Series1->LCL = lcl;
    Series1->CL = cl;
    DrawValues(DrawVec,Series1,0,1,false);
  }

  using Dew.Math;
  using Dew.Math.Units;
  using Dew.Stats.Units;
  namespace Dew.Examples
  {
    private void Example(Dew.Stats.QCSeries QCSeries1)
    {
      Vector drawvec = new Vector(0);
      Matrix data = new Matrix(0,0);
      double cl,lcl,ucl;
      StatControlCharts.QCPChart(data,drawvec,out cl,out ucl,out lcl,0.05);
      // Setup series properties
      QCSeries->UCL = ucl;
      QCSeries->LCL = lcl;
      QCSeries->CL = cl;
      MtxVecTee.DrawValues(drawVec,QCSeries1,0,1,false);
    }
  }

Declaration

Procedure QCPChart(Data: TVec; SampleSize: Integer; DrawVec: TVec; out CL, UCL, LCL: TSample; Confidence: TSample = 0.997);

Description

Calculates the P-Chart (Control chart for proportions) drawing values, center line, upper and lower control limits. Control limits are based on the normal approximation to the binomial distribution. When p is small, the normal approximation may not always be adequate. In such cases, we may use control limits obtained directly from a table of binomial probabilities. If

is small, the lower control limit obtained from the normal approximation may be a negative number. If this should occur, it is customary to consider zero as the lower control limit.

NOTE: The assumption is all samples have the same SampleSize.