Gjermund Skailand

First Name:Gjermund
Last Name:Skailand
Last Change:2015-07-26
Number of Files:19 (61st most prolific)
Number of Downloads:107,875 (71st most downloaded)

Amoeba 1.1   (details) 48 ENG   6KB/2KB
Finds the local minimum of an n-dimensional function.
By Gjermund Skailand. 1999/02/12

Chebfun 1.5   (details) 49/50 ENG   1737KB/11KB
Global root solver, minimum and maximum via Chebyshev expansions. Uses a custom parser in C, and recursively solves for all roots via eigenvalue solving of the (implicit) companion matrix. Uses a fast experimental solver. Has some utilities for Chebyshev transformation, fast parser, plotter and various FFT transformations and CDT included in the library. Parses and solves a Chebyshev expansion of size 129 in about 1 second. Can handle Chebyshev expansions up to 1025. Does not work on a regular calculator; requires a custom HPGCC ROM on a 50g to run.
By Gjermund Skailand. 2015/07/26

decMatrix 0.2   (details) 49/50 ENG   53KB/46KB
Basic real number and matrix (multiplication , addition, solving, determinant) arbitrary floating point precision using hpgcc and decNumber library. Requires the 49g+ or 50g, ARM ToolBox and LongFloat library. Faster than standard HP for 16 digits precision.
By Gjermund Skailand. 2006/11/24

Fast Knapsack   (details) 48 ENG   4KB/1KB
Fast implementation of the knapsack algorithm, which can be used, among other reasons, to fit files across multiple disks in the most optimal way. Includes source code.
By Gjermund Skailand. 2000/01/25

Fast Knapsack   (details) 49/50 48 ENG   4KB/1KB
Fast implementation of the knapsack algorithm, which can be used, among other reasons, to fit files across multiple disks in the most optimal way. Includes source code.
By Gjermund Skailand. 2000/01/25

Ibeam 49   (details) 49/50 ENG   2KB/1KB
Calculates section properties for I-beams using an input form.
By Gjermund Skailand. 1999/09/25

INT1D 1.0   (details) 49/50 ENG   102KB/1KB
Fast plotter and numerical integrals and sums of algebraic expressions using hpgcc2. Speed is 50 to 100x faster than User RPL. Sums from 1 to 100,000 in about 1 second. For the 50g and 49g+ only. Runs in RPL with stack entry mode. SD card is required (takes 80KB on the card). Full C-source is included
By Gjermund Skailand. 2010/03/08

INTPD   (details) 48 ENG   3KB/1KB
Linear interpolation utility.
By Gjermund Skailand. 1999/06/26

Linear Interpolation Utilities 2.3   (details) 49/50 48 ENG   26KB/4KB
System RPL and machine language library with linear- tabular- and double interpolation, cubic splines, linear predicting, and second and third order least squares polynomial fitting. Accepts many combinations of input. Also tested on 49g+ ROM 1.23.
By Gjermund Skailand. 2004/06/22

LongFloat 3.93   (details) 49/50 ENG   379KB/36KB
ScreenshotMultiple precision real and complex library including trig and hyperbolic functions. Interval arithmetic (precision tracking) for real functions. Algebraics with interval numbers or units may be automatically evaluated to user-defined precision. Now has basic matrix functions and 49g+/50g support.
By Gjermund Skailand and Thomas Rast. 2007/01/13

Minimax   (details) 49/50 ENG   115KB/2KB
Minimax polynomial approximation, which minimizes absolute error (not RMS). Can be used to fit data as well as functions. Implemented in User RPL, System RPL, hpgcc2 and hpgcc3 for comparison to Valentin's original implementation in HP-71 BASIC.
By Gjermund Skailand. 2009/11/01

MRQ 1.0   (details) 49/50 ENG   11KB/2KB
Levenberg-Marquardt non-linear least square fitting (calibrating) of user functions based on data. 'A*SIN(BX+C)' -> '1.1*SIN(2.2X+3.3)'. Source(System RPL and assembly language) included.
By Gjermund Skailand. 2000/09/29

MRQ 1.1   (details) 48 ENG   8KB/2KB
General non-linear least squares fitting of user defined functions. Based on Levenberg-Marquant, ref. Numerical Recipes Ch. 15.5. Includes source code.
By Gjermund Skailand. 2000/08/02

nnls 1.0   (details) 49/50 ENG   63KB/18KB
Non-negative least squares solves least squares problems subject to all results being greater or equal to 0. Possible to use result limits different from 0. Programmed in hpgcc. For the 49g+ or 50g only. Also includes freestanding version not requiring armtoolbox.
By Gjermund Skailand. 2007/04/03

PSLQ 0.22b   (details) 49/50 ENG   14KB/3KB
Integer relation finding algorithm PSLQ, with some test relations. Uses extended precision with 15-16 digits.
By Gjermund Skailand. 2004/02/03

Quaternion 1.33   (details) 49/50 ENG   16KB/6KB
Quaternions for numeric and partly symbolic handling. Displayed as 4D vectors. Written in System RPL.
By Gjermund Skailand. 2007/08/04

SETS   (details) 48 ENG   6KB/1KB
Performs basic arithmetic operations on mathematical sets, similar to logical and, or, xor, not, but for sets. Written in System RPL with included source code.
By Gjermund Skailand. 1998/08/22

Strx   (details) 48 ENG   2KB/1KB
Performs integer multiplication with enhanced precision.
By Gjermund Skailand. 1999/05/31

Utilsgcc 1.1   (details) 49/50 ENG   454KB/57KB
Multiple root polynomial solver, (approximate) polynomial GCD, polynomial division together with fast matrix solver, eigenvalues, least square solver and SVD decomposition. Programmed in hpgcc. Solves 50x50 matrix in less than 5 sec. Requires ARM ToolBox and a 49g+ or 50g.
By Gjermund Skailand. 2007/01/13

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