From 654cb632440886a3d9dda64733cd704cee9afa7a Mon Sep 17 00:00:00 2001 From: pommicket Date: Sat, 30 Jul 2016 20:39:47 -0400 Subject: Added elementary cellular automata --- all.html | 7 ++ elementarycellularautomata.html | 52 ++++++++++ js/elementarycellularautomata.js | 159 +++++++++++++++++++++++++++++ mathematical.html | 9 +- screenshots/ElementaryCellularAutomata.png | Bin 0 -> 78371 bytes 5 files changed, 226 insertions(+), 1 deletion(-) create mode 100644 elementarycellularautomata.html create mode 100644 js/elementarycellularautomata.js create mode 100644 screenshots/ElementaryCellularAutomata.png diff --git a/all.html b/all.html index e80f7f3..d463252 100644 --- a/all.html +++ b/all.html @@ -101,6 +101,13 @@ maze.

+
+Elementary cellular automata
+

+Run elementary cellular automata. +

+
+
H

diff --git a/elementarycellularautomata.html b/elementarycellularautomata.html new file mode 100644 index 0000000..92c3970 --- /dev/null +++ b/elementarycellularautomata.html @@ -0,0 +1,52 @@ + + + + + + + + +Elementary Cellular Automata + + + + + + +

Elementary Cellular Automata

+ + + +
+ +
+This is a program which runs elementary cellular automata +like Rule 110. Each cell is determined by the 3 cells above it, using +rules specified by the rule number. +
+ +Number of iterations:
+Size (if the length of the starting configuration is less than the size, zeros will be added to both sides): +
+Starting configuration:
+Rule number:
+ + +

+ + + + + + diff --git a/js/elementarycellularautomata.js b/js/elementarycellularautomata.js new file mode 100644 index 0000000..06e0df5 --- /dev/null +++ b/js/elementarycellularautomata.js @@ -0,0 +1,159 @@ +function repeatString(string, nTimes) +{ + /* + Repeats a string n times + E.g. repeatString("hi", 10) -> "hihihihihihihihihihi" + */ + return Array(nTimes+1).join(string); +} + +function bin8(x) +{ + /* + Returns an 8-digit binary representation of x, adding zeros to the start if necessary. + E.g. bin8(42) -> "00101010" + */ + var s; + for (s = x.toString(2) /* Convert to binary */; s.length < 8; s = "0" + s /* Add zero to start */); + return s; +} + +function check(b, msg) +{ + /* + If b is false, it shows the error message to the user. + Returns b. + */ + if (!b) + { + $("#error").html(msg); + } + return b; +} + + +function startingConfigValid(sc) +{ + /* + Returns true if sc is a valid starting configuration; if all of the characters in sc are 0 or 1. + */ + + for (var i = 0; i < sc.length; i++) + { + if (sc[i] != '0' && sc[i] != '1') + return false; + } + return true; +} + +function padConfiguration(config, size) +{ + /* Place zeros before and after config so that config.length = size. */ + for (; config.length < size-1; config = '0' + config + '0'); + if (config.length < size) + config += '0'; /* Add zero at end if the number of zeros must be odd (e.g. padConfiguration("1101", 9) -> 001101000) */ + return config; +} + + +function drawState(state, t) +{ + /* Draws the states */ + + + var w = $("#canvas").width(); + var h = $("#canvas").height(); + + for (var i = 0; i < w; i++) + { + if (state[i] === '1') + ctx.fillRect(i*2, t*2, 2, 2); + } +} + +function getNewValue(rule, a, b, c) +{ + /* Get new value of a cell given the three cells above it. */ + var above = a+b+c; + var binUpTo7 = ["111", "110", "101", "100", "011", "010", "001", "000"]; + return rule[binUpTo7.indexOf(above)]; +} + + +$(document).ready(function() { + $("#run").click(function() + { + $("#error").html(""); + /* An elementary cellular automaton (e.g. Rule 110 (https://en.wikipedia.org/wiki/Rule_110)) */ + var time = parseInt($("#time").val()); /* Amount of time to run the automaton for. */ + var size = parseInt($("#size").val()); /* Size of the starting automaton (bits). */ + var startingConfig = $("#start").val(); /* Starting configuration for the automaton. */ + var ruleNumber = parseInt($("#rule").val()); /* Rule number (e.g. 110). (0 <= x < 256) This must be converted to a binary number before use. */ + + if (!check(time > 0, "Error - The value " + time + " is an invalid time. Time > 0.")) + { + /* Check for invalid time argument. */ + return; + } + + if (!check(ruleNumber >= 0 && ruleNumber < 256, "Error - Rule number " + ruleNumber + " does not exist. 0 ≤ Rule number ≤ 255")) + { + /* Check for an out-of-bounds rule number. */ + return; + } + if (!check(startingConfigValid(startingConfig), "Error - Starting configuration invalid: " + startingConfig)) + { + /* Check for an invalid starting configuration. e.g. 024930283848 */ + return; + } + + if (!check(startingConfig.length <= size, "Error - Starting configuration length is greater than size!")) + { + return; + } + + if (!check(size > 0, "Error - Invalid size: " + size + ". Size > 0")) + { + /* Check for invalid size argument. */ + return; + } + + var rule = bin8(ruleNumber); + + document.getElementById("canvas").width = size*2; + document.getElementById("canvas").height = time*2; + + + ctx = document.getElementById("canvas").getContext("2d"); + + ctx.fillStyle = "#ffffff" + ctx.fillRect(0, 0, size, time); + ctx.fillStyle = "#000000" + + startingConfig = padConfiguration(startingConfig, size); + /* Run the automaton. */ + + drawState(startingConfig, 0); + + var lastState = startingConfig; + + for (var t = 1; t < time; t++) + { + var nextState = [getNewValue(rule, "0", lastState[0], lastState[1])]; + + for (var i = 1; i < size-1; i++) + { + nextState.push(getNewValue(rule, lastState[i-1], lastState[i], lastState[i+1])); + } + nextState.push(getNewValue(rule, lastState[size-2], lastState[size-1], "0")); + drawState(nextState, t); + lastState = nextState; + } + + + + + }); + + +}); diff --git a/mathematical.html b/mathematical.html index ca09c44..9482b49 100644 --- a/mathematical.html +++ b/mathematical.html @@ -56,6 +56,13 @@ Ant. You can find out more about it
+Elementary cellular automata
+

+Run elementary cellular automata. +

+
+
Maze Solver

@@ -117,4 +124,4 @@ approximates π!

- \ No newline at end of file + diff --git a/screenshots/ElementaryCellularAutomata.png b/screenshots/ElementaryCellularAutomata.png new file mode 100644 index 0000000..61ca17b Binary files /dev/null and b/screenshots/ElementaryCellularAutomata.png differ -- cgit v1.2.3