Gjermund Skailand

ID:528
First Name:Gjermund
Last Name:Skailand
Last Change:2024-12-29
Number of Files:20 (62nd most prolific)
Number of Downloads:109,400 (69th most downloaded)

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

Chebfun 1.5   (details) 49/50 ENG   1,737 KB / 11 KB
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   53 KB / 46 KB
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   4 KB / 1 KB
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   4 KB / 1 KB
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   2 KB / 1 KB
Calculates section properties for I-beams using an input form.
By Gjermund Skailand. 1999-09-25

INT1D 1.0   (details) 49/50 ENG   102 KB / 1 KB
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   3 KB / 1 KB
Linear interpolation utility.
By Gjermund Skailand. 1999-06-26

Linear Interpolation Utilities 2.3   (details) 49/50 48 ENG   26 KB / 4 KB
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 3.93Get It   (details) 49/50 ENG   342 KB / 36 KB
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

Mat Exp 2.2   (details) 49/50 ENG   1,173 KB / 44 KB
Matrix exponentials, svd, lsq and (general) eigenvalue solvers, fast multiplication and division and utilities. About 100x faster than the inbuilt routines when such exist. Written in hpgcc3 with C-source code included. Can be installed in port 2. Requires special HPGCC3-ROM, included. Makes working with larger matrixes practical on the hp50g, i.e. more or less instantaneous.
By Gjermund Skailand. 2024-12-29

Minimax   (details) 49/50 ENG   115 KB / 2 KB
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   11 KB / 2 KB
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   8 KB / 2 KB
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   63 KB / 18 KB
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   14 KB / 3 KB
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   16 KB / 6 KB
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   6 KB / 1 KB
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   2 KB / 1 KB
Performs integer multiplication with enhanced precision.
By Gjermund Skailand. 1999-05-31

Utilsgcc 1.1   (details) 49/50 ENG   454 KB / 57 KB
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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