Functions

Introduction

SAS/QC software provides specialized DATA step functions for computations related to control chart analysis, for Bayes analysis of screening designs, and for sampling plan evaluation. You can use these functions in DATA step programming statements. The following lists summarize these functions:

Table C.1: Functions for Control Chart Analysis

Function	Description
C4	expected value $c_{4}$ of the standard deviation of a sample from a normal population with unit standard deviation
CUSUMARL	average run length for a cumulative sum control chart scheme
D2	expected value $d_{2}$ of the range of a sample from a normal population with unit standard deviation
D3	standard deviation $d_{3}$ of the range of a sample from a normal population with unit standard deviation
EWMAARL	average run length for an EWMA scheme
PROBMED	cumulative distribution function of sample median
STDMED	standard deviation of median of a standard normal sample

Table C.2: Function for Bayes Analysis of Screening Designs

Function	Description
BAYESACT	posterior probabilities of variance contamination

Table C.3: Functions for Sampling Plan Evaluation

Function	Description
AOQ2	average outgoing quality for double-sampling plan
ASN2	average sample number for double-sampling plan
ATI2	average total inspection for double-sampling plan
PROBACC2	acceptance probability for double-sampling plan

In addition, the PROBBNML and PROBHYPR functions, which are provided in Base SAS software, are useful when evaluating single-sampling plans.

The twelve SAS/QC functions, together with the PROBBNML and PROBHYPR functions, are described in the Function Descriptions section. The section Details, summarizes types of sampling plans and gives additional definitions.