83 lines
1.9 KiB
JavaScript
83 lines
1.9 KiB
JavaScript
/*
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* Copyright © 2020 Luciano Iam <oss@lucianoiam.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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// This module is currently unused as 'toolkit' provides its own transformations
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// it could be still useful for developing custom widgets
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export class Scale {
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constructor (min, max) {
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this.min = min;
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this.max = max;
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this.scale = this.max - this.min;
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}
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fromWidget (val) {
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return val;
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}
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toWidget (val) {
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return val;
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}
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}
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export class DbScale extends Scale {
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constructor () {
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super(-58.0, 6.0);
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}
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fromWidget (val) {
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return this.max + this.scale * Math.log10(val);
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}
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toWidget (val) {
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return Math.pow(10.0, (val - this.max) / this.scale);
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}
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}
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export class LinearScale extends Scale {
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fromWidget (val) {
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return this.min + this.scale * val;
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}
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toWidget (val) {
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return (val - this.min) / this.scale;
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}
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}
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export class LogScale extends Scale {
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constructor (min, max) {
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super(Math.log(min), Math.log(max));
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}
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fromWidget (val) {
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return Math.exp(this.min + this.scale * val);
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}
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toWidget (val) {
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return (Math.log(val) - this.min) / this.scale;
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}
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}
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