33,072 research outputs found

    Algorithm, Proof and Performances of a new Division of Floating Point Expansions

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    We present in this work a new algorithm for the division of floating point expansions. Floating expansion is a multiple precision data type developped with arithmetic operators that use the processor floating point unit for core computations instead of the integer unit. Researches on this subject have arised recently from the observation that the floating point unit becomes a more and more efficient part of modern computers. Many simple arithmetic operators and some very usefull geometric operators have already been presented on expansions. Yet previous work presented only a very simple division algorithm. We present in this work a new algorithm. We take this opportunity to extend the set of geometric operators with Bareiss' determinant on a matrix of size between 3 and 10. Running times with different determinant algorithms on different machines are compared with other multiprec- ision packages including GMP, CADNA and a computer geometry package working with modular arithmetic

    Faster Geometric Algorithms via Dynamic Determinant Computation

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    The computation of determinants or their signs is the core procedure in many important geometric algorithms, such as convex hull, volume and point location. As the dimension of the computation space grows, a higher percentage of the total computation time is consumed by these computations. In this paper we study the sequences of determinants that appear in geometric algorithms. The computation of a single determinant is accelerated by using the information from the previous computations in that sequence. We propose two dynamic determinant algorithms with quadratic arithmetic complexity when employed in convex hull and volume computations, and with linear arithmetic complexity when used in point location problems. We implement the proposed algorithms and perform an extensive experimental analysis. On one hand, our analysis serves as a performance study of state-of-the-art determinant algorithms and implementations. On the other hand, we demonstrate the supremacy of our methods over state-of-the-art implementations of determinant and geometric algorithms. Our experimental results include a 20 and 78 times speed-up in volume and point location computations in dimension 6 and 11 respectively.Comment: 29 pages, 8 figures, 3 table

    Efficient implementation of the Hardy-Ramanujan-Rademacher formula

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    We describe how the Hardy-Ramanujan-Rademacher formula can be implemented to allow the partition function p(n)p(n) to be computed with softly optimal complexity O(n1/2+o(1))O(n^{1/2+o(1)}) and very little overhead. A new implementation based on these techniques achieves speedups in excess of a factor 500 over previously published software and has been used by the author to calculate p(1019)p(10^{19}), an exponent twice as large as in previously reported computations. We also investigate performance for multi-evaluation of p(n)p(n), where our implementation of the Hardy-Ramanujan-Rademacher formula becomes superior to power series methods on far denser sets of indices than previous implementations. As an application, we determine over 22 billion new congruences for the partition function, extending Weaver's tabulation of 76,065 congruences.Comment: updated version containing an unconditional complexity proof; accepted for publication in LMS Journal of Computation and Mathematic

    Time- and Space-Efficient Evaluation of Some Hypergeometric Constants

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    The currently best known algorithms for the numerical evaluation of hypergeometric constants such as ζ(3)\zeta(3) to dd decimal digits have time complexity O(M(d)log2d)O(M(d) \log^2 d) and space complexity of O(dlogd)O(d \log d) or O(d)O(d). Following work from Cheng, Gergel, Kim and Zima, we present a new algorithm with the same asymptotic complexity, but more efficient in practice. Our implementation of this algorithm improves slightly over existing programs for the computation of π\pi, and we announce a new record of 2 billion digits for ζ(3)\zeta(3)

    Modeling Algorithms in SystemC and ACL2

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    We describe the formal language MASC, based on a subset of SystemC and intended for modeling algorithms to be implemented in hardware. By means of a special-purpose parser, an algorithm coded in SystemC is converted to a MASC model for the purpose of documentation, which in turn is translated to ACL2 for formal verification. The parser also generates a SystemC variant that is suitable as input to a high-level synthesis tool. As an illustration of this methodology, we describe a proof of correctness of a simple 32-bit radix-4 multiplier.Comment: In Proceedings ACL2 2014, arXiv:1406.123

    Secure Numerical and Logical Multi Party Operations

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    We derive algorithms for efficient secure numerical and logical operations using a recently introduced scheme for secure multi-party computation~\cite{sch15} in the semi-honest model ensuring statistical or perfect security. To derive our algorithms for trigonometric functions, we use basic mathematical laws in combination with properties of the additive encryption scheme in a novel way. For division and logarithm we use a new approach to compute a Taylor series at a fixed point for all numbers. All our logical operations such as comparisons and large fan-in AND gates are perfectly secure. Our empirical evaluation yields speed-ups of more than a factor of 100 for the evaluated operations compared to the state-of-the-art
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