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Unformatted text preview: losest match, while the other three can be used for computing upper and lower bounds. Figure 2.25 illustrates the four rounding modes applied to the problem of rounding a monetary amount to the nearest whole dollar. Round-to-even (also called round-to-nearest) is the default mode. It attempts to ﬁnd a closest match. Thus, it rounds $1.40 to $1 and $1.60 to $2, since these are the closest whole dollar values. The only design decision is to determine the effect of rounding values that are halfway between two possible results. Round-to-even mode adopts the convention that it rounds the number either upward or downward such that the least signiﬁcant digit of the result is even. Thus, it rounds both $1.50 and $2.50 to $2. The other three modes produce guaranteed bounds on the actual value. These can be useful in some numerical applications. Round-toward-zero mode rounds positive numbers downward and negative numbers upward, giving a value Ü such that Ü Ü . Round-down mode rounds both positive and negative numbers downward, giving a value Ü such that Ü Ü. Round-up mode rounds b...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.
- Spring '10
- The American