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EWMACHART Statement |
Variable | Description |
_ALPHA_ | probability () of exceeding limits |
_INDEX_ | optional identifier for the control limits specified with the OUTINDEX= option |
_LIMITN_ | sample size associated with the control limits |
_MEAN_ | process mean ( or ) |
_SIGMAS_ | multiple (k) of standard error of E_{i} |
_STDDEV_ | process standard deviation ( or ) |
_SUBGRP_ | subgroup-variable specified in the EWMACHART statement |
_TYPE_ | type (estimate or standard value) of _MEAN_ and _STDDEV_ |
_VAR_ | process specified in the EWMACHART statement |
_WEIGHT_ | weight (r) assigned to most recent subgroup mean in computation of EWMA |
The OUTLIMITS= data set does not contain the control limits; instead, it contains control limit parameters that can be used to recompute the control limits.
Notes:
The OUTLIMITS= data set contains one observation for each process specified in the EWMACHART statement.
You can use OUTLIMITS= data sets
For an example of an OUTLIMITS= data set, see "Saving Control Limit Parameters" .
Given a process name that contains eight characters, the procedure first shortens the name to its first four characters and its last three characters, and then it adds the suffix. For example, the procedure shortens the process DIAMETER to DIAMTER before adding the suffix.
Subgroup summary variables are created for each process specified in the EWMACHART statement. For example, consider the following statements:
proc macontrol data=clips; ewmachart (gap yldstren)*day / weight =0.2 outhistory=cliphist; run;
The data set CLIPHIST would contain nine variables named DAY, GAPX, GAPS, GAPE, GAPN, YLDSRENX, YLDSRENS, YLDSRENE, and YLDSRENN.
Additionally, the following variables, if specified, are included:
For an example of an OUTHISTORY= data set, see "Saving Summary Statistics" .
Variable | Description |
_ALPHA_ | probability () of exceeding control limits |
_EXLIM_ | control limit exceeded on EWMA chart |
_EWMA_ | exponentially weighted moving average |
_LCLE_ | lower control limit for EWMA |
_LIMITN_ | nominal sample size associated with the control limits |
_MEAN_ | process mean |
_SIGMAS_ | multiple (k) of the standard error associated with control limits |
subgroup | values of the subgroup variable |
_SUBN_ | subgroup sample size |
_SUBS_ | subgroup standard deviation |
_SUBX_ | subgroup mean |
_UCLE_ | upper control limit for EWMA |
_VAR_ | process specified in the EWMACHART statement |
_WEIGHT_ | weight (r) assigned to most recent subgroup mean in computation of EWMA |
In addition, the following variables, if specified, are included:
Notes:
For an example of an OUTTABLE= data set, see "Saving Control Limit Parameters" .
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