Math.js

2020年 我要这样写代码

天涯浪子 提交于 2019-12-19 00:53:45
【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 在 9102 年年初,一位室友问我一个问题,如何才能够提升写代码的能力? 可惜的是: 当时仅仅回复了一些自己的想法,如多看开源代码,多读书,多学习,多关注业界的动向与实践,同时也列了一些原则。但是这些并没有所总结,又或者说没有例子的语言始终是空泛的。所以在今年年底之际,对应着今年中遇到的形形色色的代码问题来一一讲解一下。 好代码的用处 实际上本书建立在一个相当不可靠的前提之上:好的代码是有意义的。我见过太多丑陋的代码给他们的主人赚着大把钞票,所以在我看来,软件要取得商业成功或者广泛使用,“好的代码质量”既不必要也不充分。即使如此,我仍然相信,尽管代码质量不能保证美好的未来,他仍然有其意义:有了质量良好的代码以后,业务需求能够被充满信心的开发和交付,软件用户能够及时调整方向以便应对机遇和竞争,开发团队能够再挑战和挫折面前保持高昂的斗志。总而言之,比起质量低劣,错误重重的代码,好的代码更有可能帮助用户取得业务上的成功。 以上文字摘抄于《实现模式》的前言,距离本书翻译已经时隔 10 年了,但是这本书仍旧有着很大的价值。同时对于上述言论,我并不持否认意见。但是我认为,坏代码比好代码更加的费财(嗯,没打错,我确定)。对于相同的业务需求,坏代码需要投入的精力,时间更多,产出反而会更少。同时根据破窗理论(

how to include and use math.js

有些话、适合烂在心里 提交于 2019-12-10 11:09:45
问题 I am trying to use math.js (http://mathjs.org/docs/reference/functions/inv.html) but I can't see how to include it in an HTML file. I have read that you can include it by adding this to the file: var math = require('mathjs'); but that didn't work for me I realize this sounds like a really stupid question but I have tried to figure it out myself and have not been successful. To answer my question just show a complete HTML file (not just a bit of code from one) that successfully uses math.js

Simple Regression Prediction Algorithm in JavaScript

夙愿已清 提交于 2019-12-04 05:56:40
问题 I am trying to do a simple forecast of future profit of an organization based on the past records by using regression. I am following this link. For testing purpose, I have changed the sample data and it produced these results: My actual data will be date and profit, and they will be going up and down rather than in a contiguous increment way. I realized that the method above works for sample data which keep on increasing as the prediction is quite accurate. However, when I changed the data

Simple Regression Prediction Algorithm in JavaScript

无人久伴 提交于 2019-12-02 10:04:06
I am trying to do a simple forecast of future profit of an organization based on the past records by using regression. I am following this link . For testing purpose, I have changed the sample data and it produced these results: My actual data will be date and profit, and they will be going up and down rather than in a contiguous increment way. I realized that the method above works for sample data which keep on increasing as the prediction is quite accurate. However, when I changed the data to the one in the screenshot which goes up and down crazily, the prediction is not so accurate anymore.

JavaScript 浮点数运算的精度问题

一笑奈何 提交于 2019-11-27 11:40:50
在 JavaScript 中整数和浮点数都属于 Number 数据类型,所有数字都是以 64 位浮点数形式储存,即便整数也是如此。 所以我们在打印 1.00 这样的浮点数的结果是 1 而非 1.00 。在一些特殊的数值表示中,例如金额,这样看上去有点变扭,但是至少值是正确了。然而要命的是,当浮点数做数学运算的时候,你经常会发现一些问题,举几个例子: JavaScript 代码: // 加法 ===================== // 0.1 + 0.2 = 0.30000000000000004 // 0.7 + 0.1 = 0.7999999999999999 // 0.2 + 0.4 = 0.6000000000000001 // 2.22 + 0.1 = 2.3200000000000003 // 减法 ===================== // 1.5 - 1.2 = 0.30000000000000004 // 0.3 - 0.2 = 0.09999999999999998 // 乘法 ===================== // 19.9 * 100 = 1989.9999999999998 // 19.9 * 10 * 10 = 1990 // 1306377.64 * 100 = 130637763.99999999 // 1306377.64 *