| 释义 |
mantissa|mænˈtɪsə|
[a. L. mantissa, mantīsa makeweight; said to be of Etruscan origin.]
†1. An addition of comparatively small importance, esp. to a literary effort or discourse. Obs.
1641Maisterton Serm. 20 Trifles, which..should..as a mantissa or an overplus be cast in at their bargain. 1642Cudworth Lord's Supper i. (1676) 5 It will not be now amiss, if we add, as a Mantissa to that discourse, something of the Custom of the Heathens. 1671True Nonconf. 5 Spurning at the righteousnes of Jesus Christ, and aspiring to adde a Mantissa, an addition of your own, to his sole purchase.
2. Math. The decimal part of a logarithm.
c1865Circ. Sci. I. 519/1 The decimal part of a logarithm is called the mantissa: the whole number is called the characteristic.
Add:[2.] b. Computing. A number, usually of a fixed number of digits and between 0 and 1, by which a power of the base (e.g. 2 or 10) is multiplied to represent a number in floating-point representation.
1959M. H. Wrubel Primer of Programming for Digital Computers ii. 19 The second representation employs a mantissa, containing the significant digits, multiplied by 10 raised to a power. 1960M. G. Say et al. Analogue & Digital Computers v. 142 After multiplication has been completed the digit following the binary point must be examined and, if this digit is 0, a corrective shift must be applied to the mantissa together with an adjustment of the exponent. 1979Sci. Amer. Dec. 87/3 In most computers the decimal point in the mantissa of a floating-point number is by convention placed at the far left, so that the number 3.24 × 106 would be represented in floating-point form as .324 × 107 , or the pair of numbers 7, 324. 1985Practical Computing Aug. 102/4 Single-precision variables use a three-byte mantissa and a one-byte exponent. |