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# Using Alpha Character Variables as Predictor Variables in a Digital Computer

IP.com Disclosure Number: IPCOM000078078D
Original Publication Date: 1972-Nov-01
Included in the Prior Art Database: 2005-Feb-25
Document File: 2 page(s) / 14K

IBM

## Related People

Ghosh, SP: AUTHOR

## Abstract

Alpha characters may be used a) as predictor variables for a numerical variable, and b) in predicting equations to determine search path length.

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Using Alpha Character Variables as Predictor Variables in a Digital Computer

Alpha characters may be used a) as predictor variables for a numerical variable, and b) in predicting equations to determine search path length.

Alpha Variable Predictor of a Numerical variable. In general, alpha characters cannot be subjected to algebraic manipulation but in a digital computer, their internal representation is a (binary) decimal quantity. Thus, alpha characters can be subjected to certain types of algebraic manipulations in a digital computer. One such use is the use of alpha characters as predictor variables for a numerical variable.

Suppose y is numerical variable, which is to be predicted from a set of variables x(1), x(2), ..., x(k) where the x(i)'s can take values which are alpha or alphanumeric in character. Suppose x(i) takes the value v(i) where v(i) = (Alpha(1) Alpha(2) ...Alpha(n)). These Alpha(i)'s are alpha or alphanumeric quantities. In system 360 if Alpha(i)'s are alpha characters then the internal decimal representations of the Alpha(i)'s are one of the following decimal numbers: 193, 194, 195, 196, 197, 198, 199, 200, 201, 209, 210, 211, 212, 213, 214, 215, 216, 217, 226, 227, 228, 229, 230, 231, 232, 233. Thus, by using concatenation, v(i) can be represented by a unique decimal quantity. If Alpha(i)'s take alphanumeric values, then the numerical characters 0 to 9 are represented inside the computer in System 360 by 8-bit codes corresponding to the decimal numbers 0 to
9. Thus, whether Alpha(i)'s are alpha or alphanumeric characters, the v(i)'s have a unique decimal representation inside the computer.

Thus, though the variables x(i)'s can take values which are alpha or alphanumeric in character in the external word, inside the computer they are represented as numerical quantities.

Suppose the predicting equation is of the form

y = f(x(1), x(2), ..., x(k)). The parameters of this equation can be estimated by least square, curve fitting, or other statistical techniques on a digital computer, following similar steps as when the x(i)'s can take only numerical values.

Alpha Variables in Search Path Predicting Equations: In many information management problems, alpha character type data are stored in different locations on an auxiliary storage and they are chained together by pointers. In many applications there might be several choices of paths to reach a piece of data. In such situations, a predicting equation to predict the access time of any particular alpha character data can be d...