Computes points and limits for a p Chart - a control chart for fraction non-conforming. Number of units inspected n can be constant for all r or a constant value. Calculates both variable and constant chart limits. A range of indices for samples to be used and indices to ignore in the control calculation can also be specified. The actual number of samples used to calculate the control limits is supplied. FORMULAS: pbar = · r / · n p(i) = r(i)/n(i) UCLp = pbar + stderr mult x sqrt((pbar x (1-pbar))/n(i)) CLp = pbar LCLp = pbar - stderr mult x sqrt((pbar x (1-pbar))/n(i)) standard error = sqrt((pbar x (1-pbar))/n(i))


icon

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 defaults to the most common case where the chart limits are calculated from the data in the input array(s). 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 control chart, p-bar, is set to p0.

  • cenum.png source —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired this defaults to the most common case where the chart limits are calculated from the data in the input array(s). 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 control chart, p-bar, is set to p0.

  • cdbl.png std p0 —

    chart limit src specifies whether or not to use standard values for the chart limit calculations. If unwired this defaults to the most common case where the chart limits are calculated from the data in the input array(s). 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 control chart, p-bar, is set to p0.

  • c1ddbl.png r:# units non-conforming/sample —

  • c1ddbl.png n: sample size (variable) —

    n: sample size (variable) is the number of units inspected per sample for each value of r. Use this array if a variable number of units were inspected for each entry in r. The array length must be the same the length of the array r.

  • cu32.png n: sample size (constant) —

    (U32) Number of units in sample inspected. Use this input if the same number of units were inspected for each entry in r. Otherwise, if you are providing an array for n, leave this input unwired.

  • 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.

  • 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.

  • ii32.png # samples in calc —

    (I32) - the number of samples used in the control limits calculation.

  • i1ddbl.png p: fraction non-conforming —

    p: fraction non-conforming is the number of units non-conforming divided by the number inspected. This is the fraction non-conforming in each input sample. This is the array plotted on the p control chart.

  • i1ddbl.png UCLp —

  • i1ddbl.png LCLp —

  • inclst.png p chart limits —

    p chart limits contains the constant limits for the p chart.

  • idbl.png avg UCLp —

    p chart limits contains the constant limits for the p chart.

  • idbl.png p-bar —

    p chart limits contains the constant limits for the p chart.

  • idbl.png avg LCLp —

    p chart limits contains the constant limits for the p chart.

  • idbl.png avg std error —

    p chart limits contains the constant limits for the p chart.

    • p Chart Details

    The control limit calculations are as follows:If standard values are used for the control limit calculations, then p-bar is set to std p0, otherwise, p-bar is calculated from the input samples as specified by the index spec and indices to ignore inputs. if calculated from input data, otherwise