我刚刚学会了如何训练一个 brain.js 网络，现在正在尝试使用它。我很好奇是否可以反过来操作——从输出预测输入？

这是我的代码

const brain = require('brain.js');const network = new brain.NeuralNetwork();    /* network.train([    { input: { doseA: 0 }, output: { indicatorA: 0 } },    { input: { doseA: 0.1 }, output: { indicatorA: 0.02 } },    { input: { doseA: 0.2 }, output: { indicatorA: 0.04 } },    { input: { doseA: 0.3 }, output: { indicatorA: 0.06 } },    { input: { doseA: 0.4 }, output: { indicatorA: 0.08 } },    { input: { doseA: 0.5 }, output: { indicatorA: 0.10 } },    { input: { doseA: 0.6 }, output: { indicatorA: 0.12 } },    { input: { doseA: 0.7 }, output: { indicatorA: 0.14 } },], {  iterations: 1e6,  errorThresh: 0.00001});*/    network.fromJSON({"sizes":[1,3,1],"layers":[{"doseA":{}},{"0":{"bias":-0.7720749378204346,"weights":{"doseA":-6.819720268249512}},"1":{"bias":0.2317514568567276,"weights":{"doseA":-1.4340121746063232}},"2":{"bias":-0.34450986981391907,"weights":{"doseA":-2.9449453353881836}}},{"indicatorA":{"bias":-1.0124520063400269,"weights":{"0":-5.02399206161499,"1":-1.69333016872406,"2":-3.1710503101348877}}}],"outputLookup":true,"inputLookup":true,"activation":"sigmoid","trainOpts":{"iterations":1000000,"errorThresh":0.00001,"log":false,"logPeriod":10,"learningRate":0.3,"momentum":0.1,"callbackPeriod":10}})const result = network.run({ doseA: 0.35 });   console.log(result);// { indicatorA: 0.06978786736726761 }

但是，如果我想通过 network.run({ indicatorA: 0.07 }) 得到 { doseA: 0.35 } 呢？

我是否必须重新训练 network，但这次交换 input 和 output 的位置？还是有其他方法可以反转它？

回答：

确实有一个工具可以实现这个功能：https://github.com/BrainJS/brain.retro.js

如果有更多兴趣，我也可以提供查询工具，它允许你进行一些非常有趣的类似 MongoDB 风格的查询：https://github.com/BrainJS/brain.retro.js/blob/master/query.js