StatControlCharts.QCXChart Method

X-Chart ("XBar Chart").

public QCXChart(TMtx Data, TVec DrawVec, ref double CL, ref double UCL, ref double LCL, double Confidence);

Parameters

Parameters	Description
Data	Each Data row contains replicated observation taken at specific time.
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.
Confidence	Confidence level for upper and lower control limit. Confidence must lie in the (0,1) interval.

Remarks

This routine calculates X-Chart ("XBar Chart") drawing values, center line, upper and lower control limit.

When dealing with a quality characteristic that can be expressed as a measurement, it is customary to monitor both the mean value of the quality characteristic and its variability. Control over the average quality is exercised by the control chart for averages, usually called the XBar chart. For this chart type, the center line is defined by process grand mean and upper and lower control limits are defined by process standard deviation. Similarly, for R and S charts the center line is defined by process range and variability (standard deviation) respectively.

C# Example

The following code loads data, stored in binary file and then creates a XBar chart.

using Dew.Math;
using Dew.Math.Units;
using Dew.Stats.Units;
namespace Dew.Examples
{
  private void Example()
  {
    Matrix Data;
    Vector DrawVec;
    double cl,ucl,lcl;
    Data.LoadFromFile("ewma_data.mtx");
    StatControlCharts.QCXChart(Data,DrawVec,out cl, out ucl, out lcl, 0.025);
  }
}