## Description of SPITABCD

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When testing commands or similar forms of input for software or hardware, it is desirable to cover all possible input combinations. However, this is usually not possible in software test because of resource constraints. Only some fraction of the possible inputs may be tested.

SPITABCD generates permutations of CP/CMS commands, given the values
which the command parameters may take. The user provides these values
in an input file. The output order is of
* increasingly broad coverage *
of parameter values. This helps to eliminate the problem of deciding
which 200 of 30 zillion permutations to try, as well as which 100 to
do next if we've already tried 200.

SPITABCD uses an algorithm which produces all the possible input combinations, without repetition, in an order such that all the parameters of the command vary a great deal. Because of this greater variation of parameters, the algorithm is an improvement upon the often-used technique of producing variations using nested "DO loops". It is also better than randomly chosen parameters for situations where repetition needs to be avoided for cost or other reasons.

Also thrown in, just to give an orphan a home, is an EXEC to raise polynomials to integer powers. This EXEC was originally written to solve a "10 men each with 3 hats" combinatorics problem.

Here is what is in the SPITABCD package:

SPITABCD EXEC * The tool itself. Directions for use are in the file. SPIT2N EXEC * Improved version of SPITABCD EXEC, using pipes for * speed and allowing some additional capabilities. SPIT DATAIN * An example input file. SPITABCD LIST3270 * Human-readable explanation of the need, design, * and use of the tool. Adapted from the * unclassified technical report TR 01.C573. POLYPOWR EXEC * An unrelated REXX program to calculate the * coefficients of a polynomial raised to the Nth * power. Written mainly to demonstrate/calculate * the solution to a generalization of the problem * of finding the probability that if N men each * throw their hats in a closet and then each grabs * a hat at random, nobody winds up with their own * hat! (In the new problem, each man has 3 hats...)

SPITABCD was put together by Tim Greer, who wrote the original program and the LIST3270 documentation. Doug Breneman added SPIT2N EXEC.