forked from sheetjs/sheetjs
60 lines
1.9 KiB
JavaScript
60 lines
1.9 KiB
JavaScript
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/* xlsx.js (C) 2013-present SheetJS -- http://sheetjs.com */
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/* eslint-env node */
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var XLSX = require('xlsx');
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var pr = require('propel');
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var linest = require('./linest');
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/* generate linreg.xlsx with 100 random points */
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linest.generate_random_file(100);
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/* get the first worksheet as an array of arrays, skip the first row */
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var wb = XLSX.readFile('linreg.xlsx');
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var ws = wb.Sheets[wb.SheetNames[0]];
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var aoa = XLSX.utils.sheet_to_json(ws, {header:1, raw:true}).slice(1);
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/* calculate the coefficients in JS */
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(function(aoa) {
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var x_ = 0, y_ = 0, xx = 0, xy = 0, n = aoa.length;
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for(var i = 0; i < n; ++i) {
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x_ += aoa[i][0] / n;
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y_ += aoa[i][1] / n;
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xx += aoa[i][0] * aoa[i][0];
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xy += aoa[i][0] * aoa[i][1];
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}
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var m = Math.fround((xy - n * x_ * y_)/(xx - n * x_ * x_));
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console.log(m, Math.fround(y_ - m * x_), "JS Post");
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})(aoa);
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/* build X and Y vectors */
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var tensor = pr.tensor(aoa).transpose();
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var xs = tensor.slice(0, 1);
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var ys = tensor.slice(1, 1);
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/* compute the coefficient */
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var n = xs.size;
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var x_ = Math.fround(xs.reduceMean().dataSync()[0]);
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var y_ = Math.fround(ys.reduceMean().dataSync()[0]);
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var xx = Math.fround(xs.dot(xs.transpose()).dataSync()[0]);
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var xy = Math.fround(xs.dot(ys.transpose()).dataSync()[0]);
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var m = Math.fround((xy - n * x_ * y_)/(xx - n * x_ * x_));
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var b_ = Math.fround(y_ - m * x_);
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console.log(m, b_, "Propel");
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var yh = xs.mul(m).add(b_);
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/* export data to aoa */
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var prdata = pr.concat([xs, ys, yh]).transpose();
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var shape = prdata.shape;
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var prarr = prdata.dataSync();
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var praoa = [];
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for(var j = 0; j < shape[0]; ++j) {
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praoa[j] = [];
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for(var i = 0; i < shape[1]; ++i) praoa[j][i] = prarr[j * shape[1] + i];
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}
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/* add headers and export */
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praoa.unshift(["x", "y", "pred"]);
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var new_ws = XLSX.utils.aoa_to_sheet(praoa);
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var new_wb = XLSX.utils.book_new();
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XLSX.utils.book_append_sheet(new_wb, new_ws, "Sheet1");
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XLSX.writeFile(new_wb, "propel.xls");
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