Computes points and limits for individuals x and Moving Range Charts - control charts for mean and moving range.This VI computes the moving range over n consecutive observations where n may range from 2 to 25. A range of indices for individuals to be used and individuals to ignore in the control calculation can also be specified. The actual number of individuals used to calculate the control limits is supplied. FORMULAS: UCLx = x-bar + stderr mult x mR-bar/d2 CLx = x-bar LCLx = x-bar - stderr mult x mR-bar/ d2 standard error = mR-bar/d2 UCLmr = mR-bar + stderr mult x d3 x mR-bar/d2 CLmr = mR-bar LCLmr = mR-bar - stderr mult x d3 x mR-bar/d2 standard error = d3 x mR-bar/d2 If std error multipler = 3.0, the formulas for calculating the control limits from the data are: UCLx = x-bar + E2*mR-bar LCLx = x-bar - E2*mR-bar UCLr = D4*mR-bar LCLr = D3*mR-bar If std error multipler = 3.0, the formulas for calculating the control limits from given standard values: std sigma = std R0/d2 UCLx = std mean + 3*std sigma LCLx = std mean - 3*std sigma UCLr = D2*std sigma LCLr = D1*std sigma The constants d2, d3, E2, D1, D2, D3, and D4 are published in the table of factors and formulas for control charts for variables in ANSI/ASQC Standard A1-1987


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Inputs/Outputs

  • cnclst.png chart limit src —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired, this cluster defaults to the common case where the chart limits are calculated from the data in the input sample array. You do not have to wire this cluster unless you want the chart limits to be calculated from standard values. When using standard values, the center line for the X-bar control chart, X-bar-bar, is set to std mean, and the center line for the s control chart, s-bar, is set to std s0, or std sigma*c4.

  • cenum.png source —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired, this cluster defaults to the common case where the chart limits are calculated from the data in the input sample array. You do not have to wire this cluster unless you want the chart limits to be calculated from standard values. When using standard values, the center line for the X-bar control chart, X-bar-bar, is set to std mean, and the center line for the s control chart, s-bar, is set to std s0, or std sigma*c4.

  • cdbl.png std mean —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired, this cluster defaults to the common case where the chart limits are calculated from the data in the input sample array. You do not have to wire this cluster unless you want the chart limits to be calculated from standard values. When using standard values, the center line for the X-bar control chart, X-bar-bar, is set to std mean, and the center line for the s control chart, s-bar, is set to std s0, or std sigma*c4.

  • cdbl.png std R0/sigma —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired, this cluster defaults to the common case where the chart limits are calculated from the data in the input sample array. You do not have to wire this cluster unless you want the chart limits to be calculated from standard values. When using standard values, the center line for the X-bar control chart, X-bar-bar, is set to std mean, and the center line for the s control chart, s-bar, is set to std s0, or std sigma*c4.

  • c1ddbl.png individuals x —

    individuals x are the individual observations (or samples of subgroup size 1) on which to compute control limits.

  • cnclst.png index spec —

    (Optional) cluster of: start index (I32) - index of the first sample to include in the control limit calculation. Default is 0 or index of the first sample in samples X array. end index (I32) - index of the last sample to include in the control limit calculation. Default is 0 which selects the last sample in samples X array. If this cluster is unwired, all samples in samples X input array are included in the control limit calculation.

  • ci32.png start index —

    (I32) - index of the first sample to include in the control limit calculation. Default is 0 or index of the first sample in samples X array.

  • ci32.png end index —

    (I32) - index of the last sample to include in the control limit calculation. Default is 0 which selects the last sample in samples X array.

  • c1di32.png indices to ignore —

    indices to ignore is the indices of samples to exclude from the control limit calculation. Excluding samples is useful for eliminating out of control points from the control limit calculation. By default, this is an empty array.

  • cdbl.png std error multiplier (3) —

    (DBL, default = 3.0). Ordinarily you would leave this unwired and the control chart limits are computed as +/- 3.0 standard errors.

  • ci32.png n: sample size (2) —

    (I32) The number of individuals to use for the moving Range calculation. Min value is 2, max value is 25. Default value is 2.

  • inclst.png x-bar & mR-bar/d2 —

    x-bar is an estimate of the process mean based on the average of the individuals included in the control limit calculation.

  • idbl.png x-bar —

    x-bar is an estimate of the process mean based on the average of the individuals included in the control limit calculation.

  • idbl.png mR-bar/d2 —

    x-bar is an estimate of the process mean based on the average of the individuals included in the control limit calculation.

  • i1ddbl.png x —

    x is the individual observations. This is the array plotted on the x control chart.

  • inclst.png x chart limits —

    cluster of: UCLx (DBL) - the upper control limit for the x chart. CLx (DBL) - the center line for the x control chart. Clx = x-bar and is also the estimated process mean. LCLx (DBL) - the lower control limit for the x chart. standard error (DBL) - the standard error associated with x-bar.

  • idbl.png UCLx —

    (DBL) - the upper control limit for the x chart.

  • idbl.png CLx —

    (DBL) - the center line for the x control chart. Clx = x-bar and is also the estimated process mean.

  • idbl.png LCLx —

    (DBL) - the lower control limit for the x chart.

  • idbl.png standard error —

    (DBL) - the standard error associated with x-bar.

  • i1ddbl.png moving range mR —

  • inclst.png mR chart limits —

    cluster of: UCLx (DBL) - the upper control limit for the x chart. CLx (DBL) - the center line for the x control chart. Clx = x-bar and is also the estimated process mean. LCLx (DBL) - the lower control limit for the x chart. standard error (DBL) - the standard error associated with x-bar.

  • idbl.png UCLmr —

    (DBL) - the upper control limit for the x chart.

  • idbl.png CLmr —

    (DBL) - the center line for the x control chart. Clx = x-bar and is also the estimated process mean.

  • idbl.png LCLmr —

    (DBL) - the lower control limit for the x chart.

  • idbl.png standard error —

    (DBL) - the standard error associated with x-bar.

  • ii32.png # individuals in calc —

    (I32) The number of individuals used in the control limits calculation.

    • x & mR Chart Details

    The control limit calculations are as follows.If standard values are used for the control limit calculations, then (x-bar) is set to std mean (mR-bar) is set to std R0 or std sigma * d2, otherwise, X and mR are calculated from the input samples as specified by the index spec and indices to ignore inputs.