Starting Sequences!

qml/js/mathlib.js

@@ -23,13 +23,17 @@
 
 const parser = new ExprEval.Parser()
 
+var u = {1: 1, 2: 2, 3: 3}
+console.log(parser.parse('u[n]+u[n+1]+u[n+2]').simplify().evaluate({"u": u, 'n': 1}))
+
 var evalVariables = { // Variables not provided by expr-eval.js, needs to be provided manualy
     "pi": Math.PI,
     "π": Math.PI,
     "inf": Infinity,
     "Infinity": Infinity,
     "∞": Infinity,
-    "e": Math.E
+    "e": Math.E,
+    "E": Math.E
 }
 
 class Expression {
@@ -64,10 +68,7 @@ class Expression {
     }
     
     toString(forceSign=false) {
-        var str = this.calc.toString()
-        if(str[0] == "(") str = str.substr(1)
-        if(str[str.length - 1] == ")") str = str.substr(0, str.length - 1)
-        str = Utils.makeExpressionReadable(str)
+        var str = Utils.makeExpressionReadable(this.calc.toString())
         if(str[0] != '-' && forceSign) str = '+' + str
         return str
     }
@@ -77,6 +78,34 @@ function executeExpression(expr){
     return (new Expression(expr.toString())).execute()
 }
 
+class Sequence extends Expression {
+    constructor(name, baseValues = {}, expr) {
+        console.log('Expression', expr)
+        super(expr)
+        this.name = name
+        this.baseValues = baseValues
+    }
+    
+    isConstant() {
+        return this.expr.indexOf("n") == -1
+    }
+    
+    execute(n = 0) {
+        if(this.cached) return this.cachedValue
+        if(n in this.baseValues) return this.baseValues[n]
+        var vars = Object.assign({'n': n-1}, evalVariables)
+        vars[this.name] = this.baseValues
+        var un = this.calc.evaluate(vars)
+        this.baseValues[n] = un
+        return un
+    }
+}
+
+var test = new Sequence('u', {0: 0}, '3*u[n]+3')
+console.log(test)
+for(var i=0; i<20; i++)
+    console.log('u' + Utils.textsub(i) + ' = ' + test.execute(i))
+
 // Domains
 class Domain {
     constructor() {}

qml/js/objects.js

@@ -203,6 +203,7 @@ class Function extends ExecutableObject {
         'expression': 'Expression',
         'inDomain': 'Domain',
         'outDomain': 'Domain',
+        'comment1': 'Ex: R+* (ℝ⁺*), N* (ℕ*), Z-* (ℤ⁻*), ]0;1[, {3;4;5}',
         'labelPosition': ['above', 'below'],
         'displayMode': ['application', 'function'],
         'labelX': 'number'
@@ -280,8 +281,6 @@ class Function extends ExecutableObject {
         var pxprecision = 2
         var previousX = canvas.px2x(0)
         var previousY;
-        var draw = function(currentX) {
-        }
         if(inDomain instanceof MathLib.SpecialDomain && inDomain.moveSupported) {
             previousX = inDomain.previous(previousX)
             if(previousX === null) previousX = inDomain.next(canvas.px2x(0))
@@ -924,6 +923,8 @@ class CursorX extends DrawableObject {
     }
 }
 
+ 
+
 const types = {
     'Point': Point,
     'Function': Function,

qml/js/utils.js

@@ -207,8 +207,10 @@ function makeExpressionReadable(str) {
         [/ \^ /g, '^'],
         [/\^\(([^\^]+)\)/g, function(match, p1) { return textsup(p1) }],
         [/\^([^ ]+)/g, function(match, p1) { return textsup(p1) }],
+        [/_\(([^_]+)\)/g, function(match, p1) { return textsub(p1) }],
+        [/_([^ ]+)/g, function(match, p1) { return textsub(p1) }],
         [/(\d|\))×/g, '$1'],
-        [/×(\d|\()/g, '$1'],
+        //[/×(\d|\()/g, '$1'],
         [/\(([^)(+.\/-]+)\)/g, "$1"],
     ]
     
@@ -258,8 +260,10 @@ function parseName(str, removeUnallowed = true) {
         [/([^a-z]|^)gps(i)?([^a-z]|$)/g, '$1Ψ$3'],
         [/([^a-z]|^)gom(ega)?([^a-z]|$)/g, '$1Ω$3'],
         // Underscores
-        [/_\(([^\^]+)\)/g, function(match, p1) { return textsub(p1) }],
+        [/_\(([^_]+)\)/g, function(match, p1) { return textsub(p1) }],
         [/_([^ ]+)/g, function(match, p1) { return textsub(p1) }],
+        // Array elements
+        [/\[([^\]\[]+)\]/g, function(match, p1) { return textsub(p1) }],
         // Removing
         [/[xπℝℕ\\∪∩\]\[ ()^/÷*×+=\d-]/g , ''],
     ]
@@ -271,7 +275,6 @@ function parseName(str, removeUnallowed = true) {
     return str
 }
 
-
 String.prototype.toLatinUppercase = function() {
     return this.replace(/[a-z]/g, function(match){return match.toUpperCase()})
 }