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David's Math Pages |
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| David E. Dirkse |
Welcome at DavData, the website for:
board games, puzzles, math, freeware and Delphi programming
Delphi Information
new
catagories
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Contents
games | |
| Mini-Sudoku Solver | Assist/solve Linked-In mini-sudoku puzzles. |
| ZIP puzzle solver | Assist/solve Linked-In ZIP puzzles. |
| Binary puzzle solver | Includes hints. |
| Queens puzzle helper | Includes hints for daily Linked_In puzzle. |
| Tile puzzle | Cover surface with tiles |
| 15-puzzle | Find strategies, solve games |
| HASHI (bridges) | logistic puzzle. Hints and solutions |
| Tectonic helper version 3 | more hints, backtracking, printing |
| Tectonic | helper for number puzzles |
| Sudoku solver | great help + game analyses |
| Futoshiki | helper and solver of these number puzzles |
| The Tower of Hanoi | a puzzle for all ages |
| Tick Tack Toe (3D) | discover the winning startegy |
| Match5 | a self-learning board game |
| Colorstacks | logistic puzzle with 7 levels |
| SHIFT | the most difficult puzzle in the world |
| Jumping Goats | puzzle for all ages |
| Connect4 | single player, 8 levels, board game with analyses |
| Nim | 9 strategic board games, easy to difficult |
| Solitaire | single player puzzles |
| Sudoku Helper - Solver | select the desired amount of help |
general | |
| About DavData | |
| My Z80 home built computer | |
| My Math and Delphi programming book | articles, programs, source code |
| A chaotic pendulum | St.Mary's church, Bristol, UK. |
| A message to visitors of the Netherlands | |
| Visit to Rome | |
| Brexit ! | |
| humour | encountered during country walks in the UK |
| recycled art | |
geometry problem collection
problems 1..10
problems 11..20
problems 21..29
problems 30..39
problems 40..49
problems 50..59
problems 60..69
problems 70..79
problems 80..89
problems 1..10
problems 11..20
problems 21..29
problems 30..39
problems 40..49
problems 50..59
problems 60..69
problems 70..79
problems 80..89
math | |
| algebra problems collection | |
| the Pythagoras theorem | four very different proofs |
| Stewarts' theorem | extension of the Pythagorean lemma |
| Ptolemy's theorem | proof and application |
| Menelaus' and Ceva's theorems | plane geometry calculations |
| Rounding numbers | theory and examples |
| the sweeping rafter problem | differential calculus |
| Intersection of chords | theory + applications |
| Pythagorean Triples | algebra |
| Geometry and Statics | Statics applied to plane geometry |
| compasses and ruler constructions | basic geometry constructions with exercises + answers |
| Regular Pentagon construction | ruler & compass construction with theory |
| regular polygons | draw, investigate, use for problem solving.. |
| LCM and GCD | introduction to number theory |
| combinatorics | a short course |
| the flippo problem | calculate the probability for a complete series |
| cyclic redundancy codes | |
| a magic triangle | puzzle |
| magic squares | theory and examples |
| the grazing goat problem | trigonometric equation, numerically solved |
| circles and ellipses | translation, scaling, rotation |
| The math of epidemics | |
| difficult geometric problems | solved by rotation |
| distance of parabolas | Delphi program + analytic solution |
| basic theory of counting and coding | number theory. mod & div operators |
| Mechanics problem | trigonometry + algebra application |
| The best seat in a football stadium | geometry problem + solution |
| Hanging cable arcs calculation | explanation + Delphi program |
| The Hbot | a smart robot construction |
| How to calculate with fractions? | Includes examples |
| Newton binomium and marble boards | probabilty and gambling |
| means | arithmetic-, geometric-,harmonic means |
| the intersecting circles problem | a geometry puzzle + solution |
| Referendums | The will of the people? |
| Stemfractions | how to split a fraction into stemfractions, + program |
| The crazy circle illusion | Geometry |
| The bookmark problem | Geometry, algebra |
| Turning Radius calculation | Car or bicycle turning circle diameter |
| Introduction to Boolean Algebra | learn about AND,OR,NOT...plus examples |
| fraction ranking | calculate the rank of a fraction. Theory + Program |
| paint Lissajous curves | Graphics-Explorer makes Lissajous curves move |
| Linear Regression | find the best fitting line through a set of points |
| the Least Squares method | find the best polynomial through a set of points |
| geoproofs | geometric proofs of trigonometric identities |
| geocalc | some calculations in plane geometry |
| p calculation | calculate p using pencil and paper |
| Triangles and Sides | can these lines form a triangle? |
| Calculate square root with pencil and paper | |
| Euclid | solve Ax + By = C |
| the Ultimate Gutter | the best gutter dimensions |
| Geometry problem | tough problem, analytical solution with complex numbers |
freeware | |
| Lorentz waterwheel similator | chaotic movements |
| Pendulum simulator | measure cycle times |
| trigonometric identity tables | a base for equations |
| bit calculator | + , - ,* , / binary explained |
| static cable forces calculations | improved program and theory |
| DC networks calculator | analyse complex resistor/battery networks |
| Framework | test the strength of a frame |
| Rotating globe | full screen size |
| Computer art | painting 3D Lissajous graphics |
| Logic10: Boolean Algebra | Generate and Reduce Truth Tables |
| Prime Number Generator | program + algorithm description + source code |
| Polygon Overlap Calculator | program + algorithm description + source code |
| Graphics-Explorer | Plot, print, explore equations and functions |
| Euclid | solve Ax + By = C |
| ChrCode | show characters and codes |
| Factors | factorize numbers, calculate gcd |
| FontTest | shows how Windows renders characters on the screen |
| KeyStroke | shows the generated key codes |
| LinEq | solve systems of linear equations |
| Numbers | convert number systems |
| Pinwheel | Operate a vintage mechanical calculator |
| Ranks | Calculate the rank of a combination, permutation or partition |
Delphi programming | |
| A perfect square puzzle | solved by Delphi program |
| shortest circuit algorithm | graph theory |
| A numeric calculation of π | program + project |
| A rolling circle problem | program + project |
| Binary puzzle solutions count | program + project |
| H(ro)bot simulator | functional description + program |
| polygon expansion/contraction | program + explanation |
| find numbers | satisfying m*[ABC..]=[..CBA]; program + project |
| An integer square root algorithm | program + project |
| A cube root algorithm | program + project |
| cube diagonal distance | geometry, Delphi project |
| hexadecimal digit puzzle | program + Delphi project |
| 15-puzzle | 15-puzzle, program description |
| cat's eye | programming a cat's eye indicator |
| bitmap resizing | enlarge or reduce digital images |
| bitmap expansion | by interpolation |
| Rotation of bitmaps | theory, source code and exerciser program |
| the Xbitmap class | add many new painting features to a bitmap |
| non recursive floodfill | floodfill any shape |
| painting dash-dot lines | with multipixel pen widths | the Xfont project | create your own font |
| the Xfont class | implementation of the XFont project |
| freehand drawing | generate and store hand drawn images |
| Image compression | compresses .bmp files, for photos better than .gif |
| a rotating button component | 3D moving effect, source code + description |
| Colormixer | a simple component for dialog forms |
| Color dialog | a color dialog form with history using the colormixer |
| a microseconds counter | count program execution times with nanosecond accuracy |
| a counter component | improved microseconds counter as component |
| an arraybutton component | organise menu buttons as one- or twodimensional array |
| a simple component for color selection | quick and simple color picker |
| how to draw spirals | refresh your high-school math |
| soft drawing | Paint smooth lines and ellipses. Demo + source code. |
| Drawing | drawing techniques, part 1,2,3,4 |
| Peg-Solitaire puzzle | how to program the search for solutions |
| SHIFT puzzle | how to program the search for solutions |
| logic puzzle solving | Programming to solve logic puzzles |
| Programming the tic-tac-toe game | Includes analyses algorithm description |
| Sudoku | programming the Sudoku helper-solver |
| a Connect4 search algorithm | how the computer calculates the best move |
| formula translation | break down a math formula into basic operations |
| how to plot functions | basic theory + recognizing asymptotes. |
| Polygon Triangulation | How to dissect a complex polygon into triangles |
| the search for weird numbers | program + algorithm description | difficult geometric problem | solved by numeric method of successive approximation | a recursive GCD algorithm | program + description | recursive log claculation | program + exerciser + description | partitions generator | algorithm + description | distance of parabolas | numerical Delphi solution | Blaise Pascal magazine | lecture at IJsselstein 03-11-2018 |
| a simple billards game | program description + fysics explanation |
| a nice prime number puzzle | source code + program description |
| Weights hanging on cable | calculate cable deformations |
| Calculate logarithms | the recursive way, using chained fractions |
| Square root calculations | iterative + recursive methods |
| Pythagoras tree | small recursive program with amazing result |
| rivercross problems | Cabbage-Goat-Wolf and Jealous husbands problems + solutions |
| framework | frame test program description. |
| combinations | systematical selection of combinations. |
| color coding in image compression | an investigation. |
| a WYSIWYG math editor | how to edit algebraic equations. |
| painting a globe | from a cilindrical 2:1 projection |
| programming the Queens puzzle | program description + source code |
| Data storage in 2 dimensional arrays | Shows how data is stored in memory, allows faster access |
| InLine Help | Add InLine Help information to your application |
| Programming 3D graphics | computer art with 3D Lissajous graphics |
| Programming Truth Table Reduction | Application of Boolean Algebra |
| absolute function examples | save if statements when setting boundaries of variables |
| tree graph operations with undo | description, listing, complete project,new version 5 |
| Encryption | simple character string encryption |
| programming techniques(1) | use of the "absolute" (abs) function |
| programming techniques(2) | programming complex loops |
| programming techniques(3) | controlling a board game |
| programming techniques(4) | filtering characters for names or passwords |
| programming techniques(5) | while .. do .. loops to search arrays |
| programming techniques(6) | step by step program execution |
| programming techniques(7) | reading and writing bitstrings from/to a buffer |
| 3D spheres generator | paint / save 3D spheres in different colors |
| Floating Point numbers | explore floating point formats |
| Exponential Curve Fitting | how Graphics-Explorer builds exponential functions |
| the direction of a vector | obtain the direction of a line in degrees |
climate and energy | |
| The Pied Piper of Hamelin | the roots of climate activism |
| The Spiritual Climate | why did we turn our back to the enlightenment? |
| Climate Science | presented as cartoons |
| Energy and Progress | |
| The future of energy | |
| Energy Storage Systems | |
| Green Lies: the windfarm fallacy | |
