LogarithmPlotter/qml/js/mathlib.js

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/**
* Logarithm Graph Creator - Create graphs with logarithm scales.
* Copyright (C) 2020 Ad5001
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
.pragma library
.import "expr-eval.js" as ExprEval
const parser = new ExprEval.Parser()
class Expression {
constructor(expr) {
this.expr = expr
this.calc = parser.parse(expr).simplify()
this.replacements = [
['pi', 'π'],
['inf', '∞'],
['Infinity', '∞'],
[' * ', '×'],
['0×', '0'],
['1×', '1'],
['2×', '2'],
['3×', '3'],
['4×', '4'],
['5×', '5'],
['6×', '6'],
['7×', '7'],
['8×', '8'],
['9×', '9'],
[')×', ')'],
['×(', '('],
]
}
isConstant() {
return this.expr.indexOf("x") == -1
}
evaluate(x = 0) {
return this.calc.evaluate({
"x": x,
"pi": Math.PI,
"π": Math.PI,
"inf": Infinity,
"Infinity": Infinity,
"∞": Infinity,
"e": Math.E
})
}
toEditableString() {
return this.calc.toString()
}
toString() {
var str = this.calc.toString()
if(str[0] == "(") str = str.substr(1)
if(str[str.length - 1] == ")") str = str.substr(0, str.length - 1)
this.replacements.forEach(function(replacement){
str = str.replace(replacement[0], replacement[1])
})
return str
}
}
// Domains
class EmptySet {
constructor() {}
includes(x) { return false }
toString() { return "∅" }
static import(frm) { return new EmptySet() }
}
class Domain {
constructor(begin, end, openBegin, openEnd) {
if(typeof begin == 'number' || typeof begin == 'string') begin = new Expression(begin.toString())
this.begin = begin
if(typeof end == 'number' || typeof end == 'string') end = new Expression(end.toString())
this.end = end
this.openBegin = openBegin
this.openEnd = openEnd
this.displayName = (openBegin ? "]" : "[") + begin.toString() + ";" + end.toString() + (openEnd ? "[" : "]")
}
includes(x) {
return ((this.openBegin && x > this.begin.evaluate()) || (!this.openBegin && x >= this.begin.evaluate())) &&
((this.openEnd && x < this.end.evaluate()) || (!this.openEnd && x <= this.end.evaluate()))
}
toString() {
return this.displayName
}
static importFrom(frm) {
switch(frm.trim().toUpperCase()) {
case "R":
case "":
return Domain.R
break;
case "RE":
case "R*":
case "*":
return Domain.RE
break;
case "RP":
case "R+":
case "ℝ⁺":
return Domain.RP
break;
case "RM":
case "R-":
case "ℝ⁻":
return Domain.RM
break;
case "RPE":
case "REP":
case "R+*":
case "R*+":
case "*⁺":
case "ℝ⁺*":
return Domain.RPE
break;
case "RME":
case "REM":
case "R-*":
case "R*-":
case "ℝ⁻*":
case "*⁻":
return Domain.RME
break;
default:
var openBegin = frm.trim().charAt(0) == "]"
var openEnd = frm.trim().charAt(frm.length -1) == "["
var [begin, end] = frm.substr(1, frm.length-2).split(";")
console.log(frm, begin, end, openBegin, openEnd)
return new Domain(begin.trim(), end.trim(), openBegin, openEnd)
break;
}
}
}
Domain.R = new Domain(-Infinity,Infinity,true,true)
Domain.R.displayName = ""
Domain.RP = new Domain(0,Infinity,true,false)
Domain.RP.displayName = "ℝ⁺"
Domain.RM = new Domain(-Infinity,0,true,false)
Domain.RM.displayName = "ℝ⁻"
Domain.RPE = new Domain(0,Infinity,true,true)
Domain.RPE.displayName = "ℝ⁺*"
Domain.RME = new Domain(-Infinity,0,true,true)
Domain.RME.displayName = "ℝ⁻*"
class DomainSet {
constructor(values) {
var newVals = []
values.forEach(function(value){
newVals.push(new Expression(value.toString()))
})
this.values = newVals
}
includes(x) {
var xcomputed = new Expression(x.toString()).evaluate()
var found = false
this.values.forEach(function(value){
if(xcomputed == value.evaluate()) {
found = true
return
}
})
return found
}
toString() {
return "{" + this.values.join(";") + "}"
}
static importFrom(frm) {
return new DomainSet(frm.substr(1, frm.length-2).split(";"))
}
}
class UnionDomain {
constructor(dom1, dom2) {
this.dom1 = dom1
this.dom2 = dom2
}
includes(x) {
return this.dom1.includes(x) || this.dom2.includes(x)
}
toString() {
return this.dom1.toString() + " " + this.dom2.toString()
}
static importFrom(frm) {
var domains = frm.trim().split("")
if(domains.length == 1) domains = frm.trim().split("U") // Fallback
return new UnionDomain(parseDomain(domains[0].trim()), parseDomain(domains[1].trim()))
}
}
class IntersectionDomain {
constructor(dom1, dom2) {
this.dom1 = dom1
this.dom2 = dom2
}
includes(x) {
return this.dom1.includes(x) && this.dom2.includes(x)
}
toString() {
return this.dom1.toString() + " ∩ " + this.dom2.toString()
}
static importFrom(frm) {
var domains = frm.trim().split("∩")
return new IntersectionDomain(parseDomain(domains[0].trim()), parseDomain(domains[1].trim()))
}
}
class MinusDomain {
constructor(dom1, dom2) {
this.dom1 = dom1
this.dom2 = dom2
}
includes(x) {
return this.dom1.includes(x) && !this.dom2.includes(x)
}
toString() {
return this.dom1.toString() + "" + this.dom2.toString()
}
static importFrom(frm) {
var domains = frm.trim().split("")
if(domains.length == 1) domains = frm.trim().split("\\") // Fallback
return new MinusDomain(parseDomain(domains[0].trim()), parseDomain(domains[1].trim()))
}
}
Domain.RE = new MinusDomain("R", "{0}")
Domain.RE.displayName = "*"
function parseDomain(domain) {
if(domain.indexOf("U") >= 0 || domain.indexOf("") >= 0) return UnionDomain.importFrom(domain)
if(domain.indexOf("∩") >= 0) return IntersectionDomain.importFrom(domain)
if(domain.indexOf("") >= 0 || domain.indexOf("\\") >= 0) return MinusDomain.importFrom(domain)
if(domain.charAt(0) == "{" && domain.charAt(domain.length -1) == "}") return DomainSet.importFrom(domain)
if(domain.indexOf("]") >= 0 || domain.indexOf("]") >= 0) return Domain.importFrom(domain)
if(domain.toUpperCase().indexOf("R") >= 0 || domain.indexOf("") >= 0) return Domain.importFrom(domain)
return new EmptySet()
}