|
Hacker's Delight
''Hacker's Delight'' is a software algorithm book by Henry S. Warren, Jr. first published in 2002. It presents fast bit-level and low-level arithmetic algorithms for common tasks such as counting bits or improving speed of division by using multiplication. Background The author, an IBM researcher working on systems ranging from the IBM 704 to the PowerPC, collected what he called "programming tricks" over the course of his career. These tricks concern efficient low-level manipulation of bit strings and numbers. According to the book's foreword by Guy L. Steele, the target audience includes compiler writers and people writing high-performance code. Summary Programming examples are written in C and assembler for a RISC architecture similar, but not identical to PowerPC. Algorithms are given as formulas for any number of bits, the examples usually for 32 bits. Apart from the introduction, chapters are independent of each other, each focusing on a particular subject ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addison-Wesley Professional
Addison–Wesley is an American publisher of textbooks and computer literature. It is an imprint of Pearson plc, a global publishing and education company. In addition to publishing books, Addison–Wesley also distributes its technical titles through the O'Reilly Online Learning e-reference service. Addison–Wesley's majority of sales derive from the United States (55%) and Europe (22%). The Addison–Wesley Professional Imprint produces content including books, eBooks, and video for the professional IT worker including developers, programmers, managers, system administrators. Classic titles include '' The Art of Computer Programming'', '' The C++ Programming Language'', '' The Mythical Man-Month'', and '' Design Patterns''. History Lew Addison Cummings and Melbourne Wesley Cummings founded Addison–Wesley in 1942, with the first book published by Addison–Wesley being Massachusetts Institute of Technology professor Francis Weston Sears' ''Mechanics''. Its first comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floating-point
In computing, floating-point arithmetic (FP) is arithmetic on subsets of real numbers formed by a ''significand'' (a Sign (mathematics), signed sequence of a fixed number of digits in some Radix, base) multiplied by an integer power of that base. Numbers of this form are called floating-point numbers. For example, the number 2469/200 is a floating-point number in base ten with five digits: 2469/200 = 12.345 = \! \underbrace_\text \! \times \! \underbrace_\text\!\!\!\!\!\!\!\overbrace^ However, 7716/625 = 12.3456 is not a floating-point number in base ten with five digits—it needs six digits. The nearest floating-point number with only five digits is 12.346. And 1/3 = 0.3333… is not a floating-point number in base ten with any finite number of digits. In practice, most floating-point systems use Binary number, base two, though base ten (decimal floating point) is also common. Floating-point arithmetic operations, such as addition and division, approximate the correspond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Journal
''Linux Journal'' (''LJ'') is an American monthly technology magazine originally published by Specialized System Consultants, Inc. (SSC) in Seattle, Washington since 1994. In December 2006 the publisher changed to Belltown Media, Inc. in Houston, Texas. Since 2017, the publisher was Linux Journal, LLC. located in Denver, Colorado. The magazine focused specifically on Linux, allowing the content to be a highly specialized source of information for open source enthusiasts. The magazine was published from March 1994 to August 2019, over 25 years, before being bought by Slashdot Media in 2020. History ''Linux Journal'' was the first magazine to be published about the Linux kernel and operating systems based on it. It was established in 1994. The first issue was published in March 1994 by Phil Hughes and Bob Young, who co-founded Red Hat, and it featured an interview with Linux creator Linus Torvalds. The publication's last print edition was August 2011, issue 208. Beginning w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EE Times
''EE Times'' (''Electronic Engineering Times'') is an electronics industry magazine published in the United States since 1972. EE Times is currently owned by AspenCore, a division of Arrow Electronics since August 2016. Ownership and status ''EE Times'' was launched in 1972 by Gerard G. Leeds of CMP Publications Inc. In 1999, the Leeds family sold CMP to United Business Media for $900 million. After 2000, ''EE Times'' moved more into web publishing. The shift in advertising from print to online began to accelerate in 2007, and the periodical shed staff to adjust to the downturn in revenue. In July 2013, the digital edition migrated to UBM TechWeb's DeusM community platform. On June 3, 2016, UBM announced that ''EE Times'', along with the rest of its electronics media portfolio ( EDN, Embedded.com, TechOnline, and Datasheets.com), was being sold to AspenCore Media, a company owned by Arrow Electronics, for $23.5 million. The acquisition was completed on August 1, 2016. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Education, Inc
Pearson Education, known since 2011 as simply Pearson, is the educational publishing and services subsidiary of the international corporation Pearson plc. The subsidiary was formed in 1998, when Pearson plc acquired Simon & Schuster's educational business and combined it with Pearson's existing education company Addison-Wesley Longman. Pearson Education was restyled as simply Pearson in 2011. In 2016, the diversified parent corporation Pearson plc rebranded to focus entirely on education publishing and services; further, as of 2023, Pearson Education is Pearson plc's main subsidiary. In 2019, Pearson Education began phasing out the prominence of its hard-copy textbooks in favor of digital textbooks, which cost the company far less, and can be updated frequently and easily. As of 2023, Pearson Education has testing/teaching centers in over 55 countries worldwide; the UK and the U.S. have the most centers. The headquarters of parent company Pearson plc are in London, England. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Addison Wesley
Addison–Wesley is an American publisher of textbooks and computer literature. It is an imprint of Pearson plc, a global publishing and education company. In addition to publishing books, Addison–Wesley also distributes its technical titles through the O'Reilly Online Learning e-reference service. Addison–Wesley's majority of sales derive from the United States (55%) and Europe (22%). The Addison–Wesley Professional Imprint produces content including books, eBooks, and video for the professional IT worker including developers, programmers, managers, system administrators. Classic titles include '' The Art of Computer Programming'', '' The C++ Programming Language'', '' The Mythical Man-Month'', and '' Design Patterns''. History Lew Addison Cummings and Melbourne Wesley Cummings founded Addison–Wesley in 1942, with the first book published by Addison–Wesley being Massachusetts Institute of Technology professor Francis Weston Sears' ''Mechanics''. Its first comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Find First Set
In computer software and hardware, find first set (ffs) or find first one is a bit operation that, given an unsigned Word (computer architecture), machine word, designates the index or position of the least significant bit set to one in the word counting from the least significant bit position. A nearly equivalent operation is count trailing zeros (ctz) or number of trailing zeros (ntz), which counts the number of zero bits following the least significant one bit. The complementary operation that finds the index or position of the most significant set bit is log base 2, so called because it computes the binary logarithm . This is #Properties and relations, closely related to count leading zeros (clz) or number of leading zeros (nlz), which counts the number of zero bits preceding the most significant one bit. There are two common variants of find first set, the POSIX definition which starts indexing of bits at 1, herein labelled ffs, and the variant which starts indexing of bits at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popcount
The Hamming weight of a string is the number of symbols that are different from the zero-symbol of the alphabet used. It is thus equivalent to the Hamming distance from the all-zero string of the same length. For the most typical case, a given set of bits, this is the number of bits set to 1, or the digit sum of the binary representation of a given number and the ''ℓ''₁ norm of a bit vector. In this binary case, it is also called the population count, popcount, sideways sum, or bit summation. History and usage The Hamming weight is named after the American mathematician Richard Hamming, although he did not originate the notion. The Hamming weight of binary numbers was already used in 1899 by James W. L. Glaisher to give a formula for the number of odd binomial coefficients in a single row of Pascal's triangle. Irving S. Reed introduced a concept, equivalent to Hamming weight in the binary case, in 1954. Hamming weight is used in several disciplines including in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HAKMEM
HAKMEM, alternatively known as AI Memo 239, is a February 1972 "memo" ( technical report) of the MIT AI Lab containing a wide variety of hacks, including useful and clever algorithms for mathematical computation, some number theory and schematic diagrams for hardware – in Guy L. Steele's words, "a bizarre and eclectic potpourri of technical trivia". Contributors included about two dozen members and associates of the AI Lab. The title of the report is short for "hacks memo", abbreviated to six upper case characters that would fit in a single PDP-10 machine word (using a six-bit character set). History HAKMEM is notable as an early compendium of algorithmic technique, particularly for its practical bent, and as an illustration of the wide-ranging interests of AI Lab people of the time, which included almost anything other than AI research. HAKMEM contains original work in some fields, notably continued fractions. Introduction :Compiled with the hope that a record of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Proofs
A mathematical proof is a deductive argument for a mathematical statement, showing that the stated assumptions logically guarantee the conclusion. The argument may use other previously established statements, such as theorems; but every proof can, in principle, be constructed using only certain basic or original assumptions known as axioms, along with the accepted rules of inference. Proofs are examples of exhaustive deductive reasoning that establish logical certainty, to be distinguished from empirical arguments or non-exhaustive inductive reasoning that establish "reasonable expectation". Presenting many cases in which the statement holds is not enough for a proof, which must demonstrate that the statement is true in ''all'' possible cases. A proposition that has not been proved but is believed to be true is known as a conjecture, or a hypothesis if frequently used as an assumption for further mathematical work. Proofs employ logic expressed in mathematical symbols, along wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilbert Curves
The Hilbert curve (also known as the Hilbert space-filling curve) is a continuous fractal space-filling curve first described by the German mathematician David Hilbert in 1891, as a variant of the space-filling Peano curves discovered by Giuseppe Peano in 1890. Because it is space-filling, its Hausdorff dimension is 2 (precisely, its image is the unit square, whose dimension is 2 in any definition of dimension; its graph is a compact set homeomorphic to the closed unit interval, with Hausdorff dimension 1). The Hilbert curve is constructed as a limit of piecewise linear curves. The length of the nth curve is \textstyle 2^n - , i.e., the length grows exponentially with n, even though each curve is contained in a square with area 1. Images File:Hilbert curve 1.svg, Hilbert curve, first order File:Hilbert curve 2.svg, Hilbert curves, first and second orders File:Hilbert curve 3.svg, Hilbert curves, first to third orders File:Hilbert curve production rules!.svg, Production rules ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gray Code
The reflected binary code (RBC), also known as reflected binary (RB) or Gray code after Frank Gray (researcher), Frank Gray, is an ordering of the binary numeral system such that two successive values differ in only one bit (binary digit). For example, the representation of the decimal value "1" in binary would normally be "", and "2" would be "". In Gray code, these values are represented as "" and "". That way, incrementing a value from 1 to 2 requires only one bit to change, instead of two. Gray codes are widely used to prevent spurious output from electromechanical switches and to facilitate error correction in digital communications such as digital terrestrial television and some DOCSIS, cable TV systems. The use of Gray code in these devices helps simplify logic operations and reduce errors in practice. Function Many devices indicate position by closing and opening switches. If that device uses natural binary codes, positions 3 and 4 are next to each other but all thre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
