IMSL C# Chart Guide: CuSumStatus

IMSL C# Programmer’s Guide

Quality Control and Improvement Charts >> CuSumStatus

CuSumStatus

CuSumStatus is a tabular or status CuSum chart. The tabular CuSum statistics are

By default, both statistics have initial value zero. The parameter K is the slack value (or allowance or reference value) and is the expected mean.

The CuSumStatus chart contains two bar charts: a bar chart of above the x- axis and a bar chart of below the x-axis. There are also control limits at plus and minus H. The value of H can be set either as an absolute value or as a relative value h. They are related by , where is the standard deviation. By default, bars which are out-of-control are filled red while in-control bars are green. The data is also plotted on the chart.

The CuSumStatus has a Print method to print the and values as well as and , where is the number of consecutive periods since rose above zero.

CuSumStatus Example

This example uses the same data as used for the CuSum and EWMA examples. In this example .

(Download Code)

using Imsl.Chart2D;
using Imsl.Chart2D.QC;
using System.Drawing;

public class SampleCuSumStatus : FrameChart {
    static double[] data = {
        9.45, 7.99, 9.29, 11.66, 12.16, 10.18, 8.04, 11.46, 9.20, 10.34, 9.03,
        11.47, 10.51, 9.40, 10.08, 9.37, 10.62, 10.31, 8.52, 10.84, 10.90,
        9.33, 12.29, 11.50, 10.60, 11.08, 10.38, 11.62, 11.31, 10.52
    };

    public SampleCuSumStatus() {
        double expectedMean = 10;
        double slackValue = 0.5;

        Chart chart = this.Chart;
        AxisXY axis = new AxisXY(chart);
        CuSumStatus cusumStatus =
            new CuSumStatus(axis, data, expectedMean, slackValue);
        cusumStatus.RelativeH = 4;
        cusumStatus.Print();

        axis.AxisX.AxisTitle.SetTitle(“Sample Number”);
        axis.AxisX.AxisLabel.TextFormat = “0”;
        axis.AxisY.AxisTitle.SetTitle(“C+ / C-”);

        axis.AxisX.SetWindow(0, 30);
        axis.AxisX.AutoscaleInput = 0;

        cusumStatus.AddDataMarkers();
        cusumStatus.DataMarkers.MarkerSize = 0.5;
        cusumStatus.DataMarkers.MarkerColor = Color.Blue;
        cusumStatus.DataMarkersAxis.AxisY.AxisTitle.SetTitle(“Original Data”);

        cusumStatus.BarPlus.GetBarSet(0,0).FillType = Data.FILL_TYPE_NONE;
	 	 cusumStatus.BarMinus.GetBarSet(0,0).FillType = Data.FILL_TYPE_NONE;
	 	 cusumStatus.BarPlus.GetBarSet(0,0).FillOutlineColor = Color.Green;
        cusumStatus.BarMinus.GetBarSet(0,0).FillOutlineColor = Color.Green;
    }

    public static void Main(string[] argv) {
        System.Windows.Forms.Application.Run(new SampleCuSumStatus());
    }
}